We studied the serum lipid profiles of 29 children, 3.9-17.9 years of age who were 0.6-7.6 years after renal transplantation (Tx). Twenty normoglycemic and non-proteinuric children had a well functioning allograft and 5 children had reduced renal function. Both groups were at least 7 months on alternate day corticosteroid (ADCS) therapy. Four additional patients had good renal function but were only 2.3 +/- 0.5 months on an ADCS regimen. Fifteen normal children served as controls. The levels of serum triglycerides (STG) and total cholesterol (CHOL) were elevated and high-density lipoprotein CHOL (HDL-CHOL) were low in all patients compared to control subjects (p less than 0.01). Their cardiovascular risk factor (CHOL/HDL-CHOL) was increased. The lipid abnormalities were most prominent in Tx patients with reduced graft function. These data show that treatment with ADCS does not prevent post-Tx hyperlipidemia. More insight is needed into the mechanisms responsible for the hyperlipidemia after Tx in order to reduce possible future morbidity (and mortality) from premature cardiovascular disease in this group of young, high-risk patients.