Since the end of the 1980s, institu tes for environmental medicine have been opened throughout Germany at universities and in the public health and civil services. This was a result of the growing need for counselling of persons with environment-related disorders. Sex-specific aspects have long been neglected in medicine. Only in recent years have research projects been established to examine the biomedical risks which influence or determine differences in the spectrum of illnesses in men and women. The present study examined a cohort of patients of an environmental medicine clinic to determine whether there are also sex-specific aspects of exposure which ought to be addressed for these patients. Questionnaire data for 655 women and 501 men who visited the former environmental medicine clinic (CEM) of the former Medical Institute of Environmental Hygiene at the Heinrich Heine University Düsseldorf, Germany, between 1990 a nd 1996 with suspected environment-related health disorders were evaluated and sex-specific differences and risk factors determined using frequency distributions. The questionnaire data revealed significant sex-associated differences for behaviour-associated risk factors (e.g. less alcohol consumption (p = 0.030) and less active tobacco smoking (p = 0.040) for women than for men). The occupations carried out by women and men had different risk levels (e.g. women belonged to occupation groups with no harmful substance exposure and lighter physical work but also to occupation groups with allergy risk, skin exposure, moderately heavy to heavy physical work significantly (p = 0.001) more often than men). Men and women stated significantly different exposures both at the workplace (e.g. more exposures to noise (p = 0.012), heat (p = 0.001), dust (p = 0.007), fumes (p = 0.001), and vibration (p = 0.001) for men than for women) and at home (e.g. more exposure to cleaning agents (p = 0.001) and personal hygiene products (p = 0.043) for women than for men). In conclusion, these results require confirmation with a standardised instrumentation and objective validation where possible. Then the medical relevance of confirmed significant differences in exposure of the sexes must be determined — while allowing for possible sex differences in uptake and metabolism as well as in predisposition for effects of harmful substances. Only then shall we be able to implement preventive and — if necessary — curative measures at home and/or at the workplace.