Porter A M D (Department of General Practice, University of Edinburgh, 20 West Richmond Street, Edinburgh EH8 9DX, Scotland), Howie J G R and Levinson A. Measurement of stress as it affects the work of the general practitioner.Family Practice 1985; 2: 136–146. This paper describes a preliminary study which collected information on the work of 18 general practitioners during a total of 52 days, and also recorded their feelings of pressure and stress from hour to hour throughout each day. The instruments used to record information on day-to-day activities and to measure self-perceived pressure, stress and arousal are described. The reliability and validity of the methods used are discussed, and some suggestions made for future development. A few preliminary findings are presented.