OBJECTIVE: In Australia, accredited pharmacists perform medication reviews for patients to identify and resolve drug-related problems. We analysed the drug-related problems identified in reviews for both home-dwelling and residential care-facility patients. The objective of this study was to examine the number and nature of the drug-related problems identified and investigate differences between each type of review. SETTING: Australian patients living at home or in residential care-facilities. METHOD: We collected a nation-wide sample of medication reviews conducted between 1998 and 2005. These reviews had been self-selected by pharmacists and submitted as part of the reaccreditation process to the primary body responsible for accrediting Australian pharmacists to perform medication reviews. The drug-related problems identified in each review were classified by type and drugs involved. MAIN OUTCOME MEASURE: The number and nature of drug-related problems identified in pharmacist-conducted medication reviews. RESULTS: There were 1,038 drug-related problems identified in 234 medication reviews (mean 4.6 (+/-2.2) problems per review). The number of problems was higher (4.9 +/- 2.0 vs. 3.9 +/- 2.2; P < 0.001) in reviews for home-dwelling patients compared with care-facility residents. The number of clinically-significant problems was higher (2.1 +/- 1.1 vs. 1.5 +/- 0.7; P < 0.001) for home-dwelling patients. Oral hypoglycaemics and analgesics/antipyretics were significantly more likely to be associated with problems in home-dwelling patients than in residential care-facility patients. CONCLUSION: These data illustrate the prevalence of drug-related problems and the ability of pharmacists to identify these problems in the Australian models of medication review. The nature and frequency of problems varied between reviews for home-dwelling and care-facility patients. Such information may be used to better focus the training of practitioners based on the most frequently encountered health problems and the nature of common drug-related problems in the two settings.