To estimate the frequency of use and effectiveness in daily practice of tumor necrosis factor α (TNFα) blockers in a population with inflammatory back pain suggestive of early axial spondyloarthritis (SpA). The Devenir des Spondylarthropathies Indifférenciées Récentes (DESIR) cohort is a prospective, multicenter, observational cohort of 708 patients with early (<3 years' duration) inflammatory back pain suggestive of axial SpA. The percentage of patients receiving TNFα blockers over the first 2 years of followup was estimated by survival analysis. To evaluate effectiveness, the primary outcome (40% improvement in disease activity according to the Assessment of SpondyloArthritis international Society criteria [ASAS40]) was compared in patients who received TNFα blockers versus control patients who received any other treatment (usual care). Controls were matched to the patients based on a propensity score method. A total of 30.2% (95% confidence interval [95% CI] 26.7-33.7) patients received at least 1 TNFα blocker during the 24 months of followup. The percentage of ASAS40 responders was 31.5% (62 of 197 patients) in the group receiving TNFα blockers versus 13.2% (26 of 197) in the control group (OR 2.99 [95% CI 1.80-4.99], P = 0.0002). This effectiveness was more pronounced in the subgroup of patients with sacroiliitis identified on magnetic resonance imaging, with 46% of ASAS40 responders receiving TNFα blockers versus 15% of ASAS40 responders receiving usual care (OR 4.99 [95% CI 2.17-11.51]). Our study shows that TNFα blockers are frequently used in daily practice to treat patients with early axial SpA. Our findings confirm the effectiveness of TNFα blockers as compared to any other treatment, especially in the subgroup of patients with sacroiliitis on MRI.