The authors describe the evaluation of the implementation of an outcome measurement system (Goal Attainment Scaling-GAS) within the context of an interdisciplinary and interagency intellectual disability services setting. The GAS database allowed analysis of follow-up goals and indicated the extent of implementation, while a rater study evaluated the quality of goals. While staff were able to produce adequate goals and scales, fewer goals were set than anticipated, and the overall quality was not high. Although implementation resulted in a number of perceived benefits, various barriers to implementation were experienced. These hinged on staff perceptions of the value, ease of use, appropriateness, and soundness of the method. Widespread adoption of GAS in community intellectual disability teams is not supported by the findings of this study. The authors suggest that staff perceptions, ease of use, and the implementation process play a key role in the successful adoption of an outcome measurement system. They conclude that alternative ways of measuring individually oriented outcomes may be more useful.