Background: The objective of this retrospective cohort study was to present the experience of 20-year-long comprehensive care of pediatric patients with familial hypercholesterolemia (FH) in a single academic center. Methods and Results: The study included 84 children aged 1–18 years with FH. For the whole study group, 535 medical visits were recorded. The mean follow-up period was 33.6 months. Molecular testing performed in 55 children (65%) provided genetic confirmation of the diagnosis in 36 children (43%). Twenty-seven children (32%) were treated pharmacologically with statins. Follow-up during the treatment averaged 29 months. Treatment with statins was associated with a mean reduction in total cholesterol and LDL-cholesterol levels of 24 and 33% from the baseline. Symptoms of statin intolerance occurred incidentally and did not require amendment in the treatment protocol. Significantly higher values of body weight, height, and BMI were found only among girls older than 10 years who were treated with statins. Conclusions: These data confirm a high efficacy and a good safety profile of statin treatment in children with FH, demonstrating no harm to physical development. However, there is a need for further cause-and-effect research regarding associations between long-term treatment with low-cholesterol, low-fat diets, statin therapy, and excessive weight gain.