The best way to evaluate community health services remains the subject of much argument and debate. This paper explores difficulties encountered in the management of a randomized controlled trial of physiotherapy in a primary health care setting, and discusses conflicts which arose when carrying out a time limited commissioned evaluation of a carer support scheme. Although randomized controlled trials are still regarded as the gold standard in medical research, they can be difficult to coordinate, and often cannot be applied when patient problems are chronic or incurable and require multidisciplinary intervention. There are many cultural and organizational barriers that have to be overcome for evaluation to be successful and meaningful. If these barriers are underestimated or ignored, the quality of evaluation is compromised.