Exhibit 31.1

Rule 13a-14(a)/15d-14(a) Certification

I, Richard A. Miller, M.D., certify that:

1. I have reviewed this quarterly report on Form 10-Q of Pharmacyclics, Inc.
2. Based on my knowledge, this quarterly 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 quarterly report;
3. Based on my knowledge, the financial statements, and other financial information included in this quarterly report, fairly present in
all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in
this quarterly report;
4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures
(as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act
Rules 13a-15(f) and 15d-15(f)) for the registrant and have:
5. 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 the registrant is made known to us by others within the registrant, particularly
during the period in which this report is being prepared;
6. Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed
under our supervision to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial
statements for external purposes in accordance with generally accepted accounting principles;
7. Evaluated the effectiveness of the registrant'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
8. Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's
most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over
financial reporting;
9. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial
reporting, to the registrant's auditors and the audit committee of registrant's board of directors (or persons performing the equivalent
functions):
10. All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are
reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and
11. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's
internal control over financial reporting.



|Date: May 2, 2007 | /s/  RICHARD A. MILLER, M.D.
        Richard A. Miller, M.D.
        President and Chief Executive Officer
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