Objectives: To compare the effect of golimumab (GLM) and pamidronate (PAM) on clinical efficacy and magnetic resonance imaging (MRI) inflammation in axial spondyloarthritis (aSpA).Method: Patients who fulfilled the Assessment of SpondyloArthritis Society (ASAS) criteria for aSpA and had active disease [Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥ 4] were randomized in a 2:1 ratio to receive either GLM (50 mg) or PAM (60 mg) 4 weekly for 48 weeks. Clinical efficacy was assessed at intervals. Inflammation of the spine and sacroiliac joints (SIJs) on MRI was graded by the Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system.Results: Twenty patients were assigned to GLM and 10 to PAM (83% men; age 33.4 ± 10.9 years; disease duration 4.4 ± 3.4 years). The baseline characteristics of the two groups were similar. At week 48, the proportions of patients who achieved an ASAS20 response were not significantly different between the GLM and PAM groups (65% vs. 56%; p = 0.69). Although there were no differences in BASDAI, spinal pain, and Medical Outcomes Study 36-item Short Form Health Survey (SF-36) scores between the two groups at week 48, the Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath AS Functional Index (BASFI), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels were significantly lower in GLM-treated patients. The SPARCC scores of the spine and SIJs decreased significantly in GLM- but not in PAM-treated patients. The differences in SPARCC scores between the two groups at week 48 were statistically significant. The frequency of adverse events (AEs) was similar in both arms.Conclusions: In patients with aSpA, the clinical response rate and improvement in pain and quality of life (QoL) were similar between GLM and PAM groups after 48 weeks. However, significant reduction in inflammatory markers and MRI inflammation was only observed with GLM treatment.