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Exhibit 31

Certifications

I, John A. Schofield, Chairman of the Board, President and Chief Executive
Officer of Advanced Fibre Communications, Inc., or AFC, certify that:

1.     I have reviewed this annual report on Form 10-K of AFC;

2.     Based on my knowledge, this report does not contain any untrue statement of
a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements were
made, not misleading with respect to the period covered by this report;

3.     Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects
the financial condition, results of operations and cash flows of AFC as of, and
for, the periods presented in this report;

4.     AFCs other certifying officer and I are responsible for establishing and
maintaining disclosure controls and procedures (as defined in Exchange Act
Rules 13a-14 and 15d-14) for AFC and have:



| |  |  | (a) Designed such disclosure controls and procedures, or caused
such disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to AFC,
including its consolidated subsidiaries, is made known to us by
others within those entities, particularly during the period in
which this report is being prepared;
| |  |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| |  |  | (b) Evaluated the effectiveness of AFCs disclosure controls and
procedures and presented in this report our conclusions about the
effectiveness of the disclosure controls and procedures, as of the
end of the period covered by this report based on such evaluation;
and                                                                                           
|
| |  |  | (c) Disclosed in this report any changes in AFCs internal control
over financial reporting that occurred during AFCs most recent
fiscal quarter that has materially affected, or is reasonably
likely to materially affect, AFCs internal control over financial
reporting;                                                                                         

5.     AFCs other certifying officer and I have disclosed, based on our most
recent evaluation of internal control over financial reporting, to AFCs
auditors and the audit committee of AFCs board of directors:



| |  |  | (a) All significant deficiencies and material weaknesses in the
design or operation of internal controls over financial reporting
which are reasonably likely to adversely affect AFCs ability to
record, process, summarize and report financial data; and
| |  |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| |  |  | (b) Any fraud, whether or not material, that involves management or
other employees who have a significant role in AFCs internal
control over financial reporting.                                                                                         

|                     |  |        |  |                                      
|-------------------- |  | ------ |  | -------------------------------------
|Date: March 11, 2004 |  | By:    |  | /s/ John A. Schofield                
|                     |  |        | 
|                     |  | Name:  |  | John A. Schofield                    
|                     |  | Title: |  | Chairman of the Board,               
|                     |  |        |  | President and Chief Executive Officer

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I, Keith E. Pratt, Chief Financial
Officer, Senior Vice President, Finance and Administration and
Assistant Secretary of Advanced Fibre Communications, Inc., or AFC, certify
that:

1.     I have reviewed this annual report on Form 10-K of AFC;

2.     Based on my knowledge, this report does not contain any untrue statement of
a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements were
made, not misleading with respect to the period covered by this report;

3.     Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects
the financial condition, results of operations and cash flows of AFC as of, and
for, the periods presented in this report;

4.     AFCs other certifying officer and I are responsible for establishing and
maintaining disclosure controls and procedures (as defined in Exchange Act
Rules 13a-14 and 15d-14) for AFC and have:



| |  |  | (a) Designed such disclosure controls and procedures, or caused
such disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to AFC,
including its consolidated subsidiaries, is made known to us by
others within those entities, particularly during the period in
which this report is being prepared;
| |  |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| |  |  | (b) Evaluated the effectiveness of AFCs disclosure controls and
procedures and presented in this report our conclusions about the
effectiveness of the disclosure controls and procedures, as of the
end of the period covered by this report based on such evaluation;
and                                                                                           
|
| |  |  | (c) Disclosed in this report any changes in AFCs internal control
over financial reporting that occurred during AFCs most recent
fiscal quarter that has materially affected, or is reasonably
likely to materially affect, AFCs internal control over financial
reporting;                                                                                         

5.     AFCs other certifying officer and I have disclosed, based on our most
recent evaluation of internal control over financial reporting, to AFCs
auditors and the audit committee of AFCs board of directors:



| |  |  | (a) All significant deficiencies and material weaknesses in the
design or operation of internal controls over financial reporting
which are reasonably likely to adversely affect AFCs ability to
record, process, summarize and report financial data; and
| |  |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| |  |  | (b) Any fraud, whether or not material, that involves management or
other employees who have a significant role in AFCs internal
control over financial reporting.                                                                                         

|                     |  |        |  |                           
|-------------------- |  | ------ |  | --------------------------
|Date: March 11, 2004 |  | By:    |  | /s/ Keith E. Pratt        
|                     |  |        | 
|                     |  | Name:  |  | Keith E. Pratt            
|                     |  | Title: |  | Chief Financial Officer,  
|                     |  |        |  | Senior Vice President,    
|                     |  |        |  | Finance and Administration
|                     |  |        |  | and Assistant Secretary   

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