The aim of this study was to describe the extent and variations in administration of depot antipsychotic medication within primary care in the North Thames Region, by means of a cross-sectional survey of a sample of general practices in the North Thames Region. Outcome measures were the number of patients receiving depot at the general practice, the professionals administering depot in that general practice, and the perceived need by these professionals for further training. Depot antipsychotic medication was administered in 55 practices (79.7% of the respondents). Practice nurses gave depot antipsychotics in 41 (59.4%) of the respondents, general practitioners in 27 (39.1%) of the respondents and community psychiatric nurses (CPNs) in 31 (44.9%) of the respondents in the practices studied. It was found that the majority of GP practices within the North Thames Region administer depot antipsychotic medication, and the GPs and practice nurses share a significant proportion of this administration. Practice nurses need specific training for this task, with access to regular refresher courses to ensure good practice.