The evaluation of a health service day service for adults with learning disabilities is undertaken annually. This paper presents data charting this service over an 8-year period, 1990–1998. For the purpose of the evaluation a cohort of 12 clients have been followed over this period. The cohort represents 48% of the total clients under the health service. The study focuses on the data collected by two evaluation tools: staff completed activity-diaries and group engagement observations conducted by an independent observer. Using these tools the service is evaluated in terms of three service accomplishments (O'Brien 1986): opportunities, community presence and status. Each accomplishment is discussed with reference to the data collected over time and the progress made by the service in meeting these. Results over this period demonstrate an increase in the range of activities offered to clients, an increase in the percentage of community based activities, a decrease in the group size in community activities and increased engagement levels. These results suggest that the service has made considerable progress in meeting its goals. Conclusions are reached both on the services progress and on the worth of the evaluation process in day services.