An increase in reports of systemic lupus erythematosus (SLE) related to tumour necrosis factor inhibitor (TNFi) therapy has recently been highlighted. We report new-onset SLE in a 22-year-old woman after 13 months of infliximab for ankylosing spondylitis (AS). Lupus symptoms promptly resolved and serologic abnormalities improved after infliximab was ceased. A flare of AS symptoms after 2 months prompted cautious introduction of an alternative TNFi, etanercept. At 14 months follow-up, neither clinical nor serologic flare of lupus had occurred. To our knowledge, this is the third reported case of infliximab-related lupus that did not recur on switching to an alternative TNFi.