There is a lack of evidence about the efficacy of routinely used interventions in shoulder pain, such as corticosteroid injection and physiotherapy. This pilot study was set up to assess the feasibility of a larger, randomized controlled trial. Patients with the clinical presentation of a painful arc of less than 6 months' duration were recruited through their general practitioners. A total of 112 patients were randomized to 4 groups: control, physiotherapy, a course of subacromial steroid injections, or both physiotherapy and steroid injections. The primary outcome measure was the Oxford Shoulder Score (OSS). Follow-up was 18 weeks and by postal questionnaire at 1 year. No significant differences were found within groups between the OSS scores or the Physical Health total of the Medical Outcomes Study Short Form 36 (SF-36) Health Survey at the beginning and end of the trial or at 1 year. By analysis of covariance, no significant differences were found between treatment groups. Larger studies are needed. A power calculation from our data suggests recruitment of more than 800 patients would be required to achieve a 90% chance of a clinically significant difference being detected between these groups.