The aim of this work is to present a clinical questionnaire for epidemiological studies in occupational allergology. We have evaluated and tested the items of such a questionnaire, finding a good sensitivity and specificity in terms of identification of symptoms and a clinical approach to the patient. The questionnaire was blind tested by two specialists and their results were found to be concordant. We realized that such a questionnaire is an easy instrument to use for medical personnel, reproducible and reliable. It can be applied in well orientated studies of occupational medicine as a first step in the investigation of work-related symptoms and in monitoring the workplace.