26 randomized controlled trials were included in this network meta-analysis on the comparative efficacy of 20 different non-steroidal anti-inflammatory drugs in patients with ankylosing spondylitis. In total, 15 of the 20 NSAIDs demonstrated a significant effect on short-term pain compared to placebo. The greatest effect size was observed with etoricoxib use, which also demonstrated significantly greater efficacy compared to celecoxib, ketoprofen, and tenoxicam. Only sulindac demonstrated a statistically significant increase in the incidence of gastrointestinal adverse events compared to placebo.