This study is to assess the potential factors that could affect the serum prostate-specific antigen (PSA) level in healthy younger men. We evaluated the associations of age, body mass index (BMI) and serum lipid profile with serum PSA level in 6774 Chinese men (aged 20-49 years) who received a routine health examination. Eligible men were classified into 10-year age groups. BMI was categorized as underweight (<18.5), normal (18.5-22.9), overweight (23.0-24.9), obese (25.0-29.9) and very obese (>30) according to the redefined World Health Organization (WHO) criteria for the Asia-Pacific region. PSA levels were compared among groups as well. In multiple linear regression analysis, PSA was positively correlated with age (P<0.0001). Negative correlations existed between PSA and BMI (P<0.0001) and triglyceride level (P=0.01). No relationship could be found between PSA and serum cholesterol (P=0.711) or high-density lipoprotein (HDL; P =0.665). In addition, we found that serum PSA levels increased with age and decreased with BMI. Our study demonstrates that age, BMI and triglyceride levels influence the PSA level in men <50 years of age.