To assess the effect of severe inactivity on the serum lipid and lipoprotein profile, 21 quadriplegic men between the ages of 24 and 47 were compared with 20 age-matched healthy control men. The group of quadriplegic men had significantly lower levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), HDL2-C and HDL3-C. The current recommendation for desirable TC is less than 200 mg/dl, whereas HDL-C of less than 35 mg/dl is considered a risk factor for coronary heart disease. Of the 50% (10/20) of the men in the normal control group who had a desirable TC, only 10% (1/10) had a low or undesirable HDL-C value. In comparison, although 81% (17/21) of the group of quadriplegic men had a desirable TC, 53% (9/17) of these individuals had a low HDL-C level. It is concluded that although the presence of lower TC could be beneficial in QM, the decreased values of HDL-C and HDL2-C and the increased ratio of TC/HDL-C suggest a higher risk of coronary heart disease. The findings are consistent with recent reports of an increased prevalence of coronary heart disease in spinal cord injury patients, which could be due to an abnormal lipoprotein profile related to diet, inactivity, changes in body composition, and life style. Moreover, the present data suggest that HDL-C should be measured in quadriplegic men with modifiable risk factors, even if they have desirable TC, to avoid missing an increased coronary heart disease risk status.