Risk factors associated with low back disorders have been examined using the records of 3920 patients over the age of 18 years who entered a model family practice unit during the period from 1975 to 1978. The daily activities and characteristics of each of the individuals was divided into various risk factors including sedentary and driving occupations, drivers of trucks, hours of sitting, number of term pregnancies, vibration exposure not incurred while driving, lifting, carrying, pushing, smoking, sports, stressful events, bending, twisting, and pulling. Each of the patients was detailed regarding sex, age, reported incidents of low back pain, episodes of low back pain necessitating medical attention, referral to specialists, hospitalization, number of weeks lost from work, and precipitating life events. Psychological factors which appeared to be linked to low back pain included anxiety, depression, and stressful life events. Even so, a direct cause and effect relationship was not demonstrated by this study. Truck driving, lifting, carrying, pushing, pulling, bending, twisting, and vibration exposures were all identified as having significant relation to low back pain. An unexpected finding was an association between smoking and low backpain. One reason for this connection may be the existence of a chronic cough among the smokers which resulted in mechanical stresses placed on the lower portion of the back.