This study aimed to measure the outcomes of a harmonised, structured pharmaceutical care programme provided to elderly patients (> or =65 years of age) by community pharmacists in a multicentre international study performed in 7 European countries. The study was a randomised, controlled, longitudinal, clinical trial with repeated measures performed over an 18-month period. A total of 104 intervention and 86 control pharmacy sites participated in the research and 1290 intervention patients and 1164 control patients were recruited into the study. A general decline in health-related quality of life over time was observed in the pooled data; however, significant improvements were achieved in patients involved in the pharmaceutical care programme in some countries. Intervention patients reported better control of their medical conditions as a result of the study and cost savings associated with pharmaceutical care provision were observed in most countries. The new structured service was well accepted by intervention patients and patient satisfaction with the services improved during the study. The pharmacists involved in providing pharmaceutical care had a positive opinion on the new approach, as did the majority of general practitioners surveyed. The positive effects appear to have been achieved via social and psychosocial aspects of the intervention, such as the increased support provided by community pharmacists, rather than via biomedical mechanisms. This study is the first large-scale, multicentre study to investigate the effects of pharmaceutical care provision by community pharmacists to elderly patients. Future research methodology and implementation will be informed by the experience gained from this challenging trial.