A study was carried out in general practice to investigate the effectiveness and tolerance of a fixed-dose combination of timolol maleate (10 mg) and bendrofluazide (2.5 mg) in 20 hypertensive patients who had been difficult to control with previous antihypertensive therapy. Patients were started initially on 2 tablets daily and the dose titrated at weekly intervals up to a maximum of 4 tablets daily or until normotension was achieved. If patients failed to respond adequately at this dosage level, prazosin (0.5 mg twice daily) was added to the regimen. At the end of the trial period of 16 weeks, 11 patients were controlled on timolol/bendrofluazide alone as were 8 of the other 9 patients after the addition of prazosin: 1 patient showed a variable response, probably due to poor compliance. Side-effects were either self-limiting or could be eliminated by alterations in the dosage regimen and there were no episodes of hypotension. It is concluded that the small group of patients with mild to moderate hypertension who are relatively resistant to standard therapy can be controlled in general practice by the judicious use of a combination of timolol/bendrofluazide and prazosin with no increase in side-effects or reduction in compliance.