EXHIBIT 21.1

VIA NET.WORKS, INC.  CORPORATE STRUCTURE AS OF DECEMBER 31, 2002

The following table indicates the name, subsidiary relationships and jurisdiction of formation of VIA NET.WORKS, Inc.'s direct and indirect subsidiaries.

|Name                                 |                                     | Jurisdiction of
Formation                                       
|------------------------------------ | ----------------------------------- | ----------------------------------------------------------------
|1. VIA NET.WORKS NY Corp.            |                                     | New York                                                        
|2. VIA NET.WORKS Holdco, Inc.        |                                     | Delaware                                                        
|                                     | A VIA NET.WORKS Europe Holding B.V. |                                                                 
|                                     |                                     | 1. VIA NET.WORKS Nederland B.V. (100%)                          
|                                     |                                     | 2. bART Holding B.V. (100%)                                     
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     | 3. VIA NET.WORKS Portugal-Tecnologias de Informacao, S.A. (100%)
|                                     |                                     |                                                                 
|                                     |                                     | 4. VIA NET.WORKS Espana, S.L. (100%)                            
|                                     |                                     | 5. VIA NET.WORKS IRUCo. Limited (100%)                          
|                                     |                                     | 6. VIA NET.WORKS Deutsche Holding GmbH (100%)                   
|                                     |                                     | 7. VIA NET.WORKS Deutschland GmbH (100%)                        
|                                     |                                     | 8. VIA NET.WORKS U.K. Holding Limited (100%)                    
|                                     |                                     | 9. VIA NET.WORKS U.K. Limited (100%)                            
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     |                                                                 
|                                     |                                     | 10. VIA NET.WORKS Holdco Italy S.r.L(90%)                       
|                                     |                                     | 11. VIA NET.WORKS Italia S.p.A. (100%)                          
|                                     |                                     | 12. VIA NET.WORKS (Schweitz) AG (100%)                          
|                                     |                                     | 13. VIA NET.WORKS France Holding SAS                            
|                                     |                                     | 14. VIA NET.WORKS France S.A.(100%)                             
|3. VIA NET.WORKS Holding Cayman      |                                     | Cayman Islands                                                  
|                                     | A. ServiceNet S.A. (100%)           |                                                                 
|4. SurfTrade U.S.A., Inc. (100%)     |                                     | Delaware                                                        
|                                     | A. SurfTrade Portugal S.A.          |                                                                 
|5. VIA NET.WORKS U.S.A., Inc. (100%) |                                     | Georgia                                                         

---

QuickLinks