Objective To investigate lipoprotein(a) [Lp(a)], oxidized Lp(a) [ox-Lp(a)] and Lp(a) immune complex [Lp(a)-IC] levels in children with nephrotic syndrome (NS). Design and methods Plasma Lp(a), ox-Lp(a) and Lp(a)-IC levels were determined in 106 NS children in acute-period, 42 in remission and 155 controls. Results Lp(a) and ox-Lp(a) levels were significantly higher in acute-period and remission NS than in control. Ox-Lp(a) levels in acute-period NS were higher than in remission. Lp(a)-IC levels in acute-period NS were higher than in control. Lp(a), ox-Lp(a) and Lp(a)-IC were found negatively related with albumin in NS. Lp(a), ox-Lp(a) and Lp(a)-IC levels decreased after use of steroid therapy. Multiple linear regression analysis found relative change of albumin, creatinine, urea, triglyceride and high density lipoprotein cholesterol accounted for 78.9% of variation in ox-Lp(a). Conclusions Lp(a), ox-Lp(a) and Lp(a)-IC levels were increased in NS children, which may play an important role in the processes of atherosclerosis.