There is increasing interest in the acquisition and measurement of physical fitness in general populations (Bassey and Fentem 1981). Measuring fitness can be uncomfortable and exhausting for subjects and expensive and time-consuming for experimenters (Andersen et al. 1971). Various authors have described and/or evaluated methods for the prediction of VO2 max (Astrand and Rhyming 1954, Davies 1968, Fitchett 1985, Harrison et al. 1980, Jette 1979, Jette et al. 1982, Shephard 1975, Shephard et al. 1979). A valid, safe, socially-acceptable alternative for such measurements applicable to a population would be of benefit. Asking subjects how they perceive their own physical fitness might be such an alternative. The validity and reliability of the data contained from such a questionnaire could be tested against conventional measures of physical fitness. A study which incorporated questionnaire surveys as one method of determining physical fitness in a large population was undertaken on Fire Service personnel in England, Scotland, and Wales (Ellam et al. 1985); a subsample of the population were questioned in the same way but in addition their fitness was assessed by physiological measurements. This paper describes the characteristics of the physical fitness of an average fireman as revealed by responses to questionnaires and how firemen felt their fitness was related to their working duties; it further examines these in relation to objective measurements.