The relationship between peak VO2 and serum lipids, lipoproteins, and apolipoproteins was assessed in nine traumatic spinal cord injured (SCI), active, male volunteers. Mean (SD) age, height, and weight were 30.6 (11.6) yr, 171.1 (11.3) cm, and 74.2 (12.5) kg, respectively. Peak VO2 (X = 2.13 l.min-1) was assessed by a graded arm-crank test to maximum, percent body fat (X = 28.7%) by densitometry, and lipid profile by measures of serum triglycerides, total cholesterol (TC), high and low density lipoprotein cholesterol (HDL-C and LDL-C, respectively), apolipoproteins (apoA-1, apoB), and various ratios of lipids, lipoproteins, and apolipoproteins. Significant inverse relationships emerged between peak VO2 and TC/HDL-C (r = -0.86; P less than 0.01), apoB/apoA-1 (r = -0.75; P less than 0.05), triglycerides (r = -0.73; P less than 0.05), and LDL-C/HDL-C (r = -0.72; P less than 0.05). Direct correlations (P less than 0.05) were demonstrated between peak VO2 and apoA-1/apoB (r = 0.71) and HDL-C/apoA-1 (r = 0.64). The present results indicate that, for active, mid-to-lower thoracic SCI men, the putative atherogenic and antiatherogenic lipid, lipoprotein, and apolipoprotein indices are significantly related to peak VO2 in a manner similar to that described for the able-bodied. These findings indicate the relevance of aerobic fitness assessment in planning CHD prevention strategies for the SCI.