A retrospective chart analysis of 200 consecutive, cyclosporine-treated, renal allograft recipients, transplanted between January 1988 and June 1992, was conducted to determine the incidence of and the etiologic variables for post-transplant hypercholesterolemia. In addition, the effectiveness of dietary intervention alone or in combination with gemfibrozil (600 mg b.i.d.), in post-transplant hypercholesterolemia was evaluated. Hypercholesterolemia (> or = 240 mg/dl on two separate determinations, while on maintenance immunosuppression) was present in 138 patients (Group A-69%). When compared to the remaining 62 patients without hypercholesterolemia (Group B-31%), there were no differences in mean age, body weight at transplantation, race, incidence of overt diabetes, systolic and diastolic blood pressure, or serial serum creatinine, albumin, and cyclosporine levels between these groups. Post-transplant hypercholesterolemia was significantly more prevalent in females, in recipients with higher baseline serum total cholesterol levels (mean +/- SEM, Group A = 229.0 +/- 5.0 vs. Group B = 192.0 +/- 6.1 mg/dl, p < 0.001), and in recipients with an elevated fasting blood glucose at 1 year post-transplant (Group A = 150.5 +/- 10.5 vs. Group B = 105.2 +/- 10.7 mg/dl, p < 0.05). In all patients with hypercholesterolemia, a hypocaloric low fat and low cholesterol (< 300 mg/day) diet was initiated at a mean of 0.59 +/- 0.06 years after transplantation with grading of dietary compliance at each follow-up visit (Grade 1, < 300 mg cholesterol; Grade 2, 300-500 mg cholesterol; Grade 3, > 500 mg cholesterol intake in 24 hours).(ABSTRACT TRUNCATED AT 250 WORDS)