The objective of this study was to assess the effect of infliximab on depression, anxiety and quality of life in patients with active ankylosing spondylitis (AS). In this 6-week longitudinal study, 16 patients with AS were assessed. Active disease as defined by BASDAI ≥4.0 was sought for inclusion. Infliximab was administered 5 mg/kg at 0, 2 weeks and 6 weeks. Collected data included age, sex and date of onset of rheumatologic disease. Activity of disease was measured using Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Biological activity was evaluated with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). ESR and CRP were assessed at baseline and day 42. The Hospital Anxiety and Depression scale (HADS), Beck Depression Inventory (BDI) and 36-item Short Form Health Survey (SF-36) were used to evaluate anxiety, depression and quality of life. BASDAI, SF-36, HADS and BDE were assessed prior to the initial infliximab dose and at 2nd, 14th and 42nd day. Seven (43.8%) AS patients had depression scores above the cut off value for both the HADS depression (HADS-D) and BDI and 4 (25 %) had high HADS anxiety scores at baseline. Significant time effect for BDI and HADS-D scores were observed. Although significantly lower BDI scores were found after first, second and third infusions of infliximab, compared to initial score, the significant decrease in HADS-D appeared after second and third infusions. A significant time effect for HADS-anxiety scores were found as well. All of the subscales of SF-36 improved significantly during the course, with an exception of role emotional, for which the difference approached to the significance. The change in BASDAI scores and CRP and ESR, in the treatment process, were not correlated with the change in depression and anxiety scores. Infliximab which is an anti-TNF-α drug, may be effective in the treatment of depression accompanying AS. Possible implications for the treatment of major depressive disorder were discussed, as well.