The management of hypercholesterolemia in children remains controversial, and the effectiveness of long-term follow-up in a specialized lipid disorders clinic has not been studied. To determine trends in growth parameters and lipid values related to diet, medication and ongoing education, we reviewed data from a prospectively maintained database in a pediatric lipid disorders clinic of patients with familial hypercholesterolemia (FH) followed for more than 5 years with more than 5 visits. From 1972 to 1990, 119 eligible children(54% males) with FH were initially seen at a median age of 7.7 y (range, 0.4 to 16.8 y) and were followed for a mean of 20 ± 9 (SD) visits over a mean of 10.0 ± 3.7 y. The mean initial total cholesterol (TC) level was 7.30 ± 1.54 mmol/L. All patients were gradually placed on an AHA Step 2 low-fat diet. Medication was used in 65 (55%) patients: Colestipol, 22; cholestyramine, 57; lovastatin, 7; and gemfibrozil; 2. Weight percentiles increased by a mean of +1.6 ± 3.3% per year (p=0.0001) and this was related to trends of increasing TC (r=0.40; p=0.0001) and triglycerides(r=0.26; p=0.005), and to older age at first visit (r=0.20; p=0.03). TC did not change significantly (+0.02 ± 0.16 mmol/L per year; p=0.21) during follow-up. Trends of decreasing TC were noted for patients with higher initial TC (r=0.22; p=0.02) and younger age (r=0.26; p=0.004), and were not related to medication use. Progressive lipid-lowering is more readily achieved for children with FH with higher initial TC and referred at an early age, but approval and use of more acceptable and effective medications is needed. Growth is unaffected; obesity may complicate effectiveness.