The views of users of services have traditionally been sought through the use of 'patient satisfaction' surveys. Because such surveys are often devised by service providers there are concerns that their use as evaluation tools may be flawed due to issues of power and passivity, and that they do not represent active involvement by service users in the feedback loop. The Newcastle Crisis Assessment and Treatment Service offers treatment at home to people in mental health crisis who would otherwise be admitted to hospital. This article reports on the process of inviting previous users of a home treatment service to give their views about what was most important to them about receiving the service. A participatory research approach combining a two-stage modified Delphi study and semi-structured interviews conducted by service user interviewers were employed to gather rich data to inform the construction of a service evaluation questionnaire. The questionnaire is now in routine use for every person who is in receipt of treatment at home. The feedback obtained from the questionnaire will be used to shape and refine the service provided by the team. As a 'live' document through use and feedback, the questionnaire will continue to evolve in order to retain its sensitivity and relevance.