This study is based on a questionnaire which focused on the possible association between life-style factors and male fertility in a group of 252 men attending our laboratory in connection with a fertility investigation. Their answers were correlated to sperm quality. No association could be documented between sperm quality and smoking habits, coffee drinking, a moderate alcohol intake, exposure to heat (sauna, hot baths, type of underwear, sedentary activities), or physical activities in their leisure time. In contrast, the reported average ejaculation frequency was significantly positively correlated to the motility of the sperm (% progressive), and inversely related to the proportion of sperm with abnormal morphology and semen volume. This indicates that the life style of the subject has little if any impact on semen quality, at least within the limits recorded in the present study.