The association between seronegative spondyloarthro- pathies and IgA nephropathy is well documented, mainly in cases of ankylosing spondylitis (AS). However, although these diseases have been associated, the physiopathological links between each other appear unclear. Anti-TNFalpha agents have transformed the outcome of axial forms of AS resistant to conventional anti-inflammatory therapies. Infliximab, a monoclonal anti-TNFalpha antibody, has greatly improved the evolution of AS although several adverse events have been described. On the other hand, infliximab has been demonstrated to reduce renal symptoms associated with chronic inflammatory rheumatological diseases, such as amyloid A (AA) amyloidosis, but few data are available on its efficacy in controlling IgA nephropathy associated with AS [1,2]. We report here a case of IgA nephropathy associated with AS that became symptomatic, whereas infliximab therapy efficiently controlled the rheumatological disease. This suggests that even though infliximab therapy effectively controls rheumatological manifestations, it may not be able to prevent IgA nephropathy associated with AS. Thus, this case report illustrates the complexity of the physiopathology of both diseases.