OBJECTIVE: To study the usefulness of moclobemide and amitriptyline in the treatment of fibromyalgia (FM) in females without psychiatric disorder. METHODS: In the present four centre, 12 week study, 130 female FM patients not suffering from psychiatric disorders were randomized to receive amitriptyline (AMI; 25 37.5 mg), moclobemide (MOCLO; 450-600 mg) or identical placebo. RESULTS: Seventy-four, 54 and 49 per cent of patients on AMI, MOCLO and placebo, respectively, were judged as responders. The patients on AMI also managed best regarding the respective improvements during the trial in general health, pain, sleep quality and quantity, and fatigue on visual analogue scales (VAS), the areas of the Nottingham Health Profile (NHP), as well as in the three Sheehan's functional disability scales. In the within-group comparisons, MOCLO also improved pain assessed both on VAS and on the NHP pain dimension, but the improvement was invalidated by the poor success of the drug with regard to sleep. The tolerabilities of all three drugs were comparable. CONCLUSION: The study indicates that MOCLO may not be helpful in FM patients free from clinically meaningful psychiatric problems.