Lymphoma is an increasingly well-recognized complication in patients receiving anti-tumour necrosis factor (TNF) therapies. We report a case of a man who presented with diffuse large B-cell lymphoma (DLBCL) while being treated with adalimumab for rheumatoid arthritis (RA) which showed complete, spontaneous regression following withdrawal of TNF inhibition. This case highlights the need for increased vigilance for lymphoma in patients receiving anti-TNF treatment; and in patients who develop lymphoma while receiving anti-TNF therapy, a trial of withdrawal of this medication, and monitoring for regression, should be considered where possible, before commencing chemo- or radiotherapy.