The Surgery Satisfaction Questionnaire (SSQ) was developed using the methods of psychological test construction, and designed to determine patients' satisfaction with the services offered to them by their general practitioners. Principal components analysis (PCA) revealed five components distinct from general satisfaction--continuity, accessibility, availability, medical care and premises. Reliability as determined by a split-half test (coefficient alpha) was adequate but should be improved in future versions of the questionnaire. A study of criterion validity was undertaken to test the questionnaire and to develop methods of testing the validity of measures of patient satisfaction. The two criteria used were the doctors' self-assessment of their own practices and the assessment of an external assessor. The findings supported the validity of the components of continuity, accessibility, availability and premises, but the patients' scores correlated better with the external assessors' scores than the doctors' self-assessed scores. SSQ is a useful foundation for the development of measures of patient satisfaction in general practice.