Scavenging and reverse transport of atherogenic oxidized lipids by high-density lipoprotein (HDL) was recently suggested to contribute to atheroprotection. We investigated the associations of oxidized HDL lipids (oxHDLlipids) with known risk factors for atherosclerosis in a population-based cross-sectional study of 1395 Finnish adults ages 24-39 years (54.9% women). Analysis of oxidized lipids in isolated HDL and LDL (oxLDLlipids) was based on the determination of conjugated dienes. Oxidized LDL was measured also with a method based on antibodies against oxidized Apo-B (oxLDLprot). Serum lipids and risk factors were measured. In multivariable models, oxHDLlipids were associated inversely with age (partial R(2)=2.9% in men, 0.8% in women) and directly with oxLDLlipids (partial R(2)=3.4% in men, 4.2% in women) after adjustment for Apo-A1 (partial R(2)=9.6% in men, 25.2% in women). In men, oxHDLlipids were also associated inversely with insulin (partial R(2)=1.1%). In women, oxHDLlipids were additionally inversely associated with waist circumference (partial R(2)=1.8%) and daily smoking (partial R(2)=0.7%) and directly with C-reactive protein (CRP; partial R(2)=0.5%) and alcohol use (partial R(2)=0.5%). We conclude that an elevated risk profile characterized primarily by advanced age is associated with lower oxHDLlipid levels in a population of young Finnish men and women. Higher levels of oxHDLlipids are additionally associated with higher oxLDLlipid levels. In men, higher insulin levels are also associated with lower oxHDLlipid levels. In women, increased waist circumference and daily smoking are also associated with lower oxHDLlipid levels, and higher CRP levels and alcohol use are associated with higher oxHDLlipid levels.