The clinical diagnosis of familial hypercholesterolemia (FH) in children is based on family history and laboratory findings. The best available value of low-density lipoprotein cholesterol (LDL-C) for the diagnosis of FH in children is >3.50 mmol/L (>135 mg/dL) when FH runs in the family. Levels below this concentration were only found in 4.3% of children that had a mutation in the LDL-receptor gene. In contrast, children with LDL-C equal to or above 3.50 mmol/L had 0.98 posttest probability of FH. Untreated FH carries a substantial burden of morbidity and mortality if left untreated or if inadequately treated. The guidelines of the American National Cholesterol Education Program suggested that drug treatment should be considered from the age of 10 years if LDL-C levels are greater than or equal to 4.9 mmol/L (190 mg/dL) or greater than or equal to 4.1 mmol/L (158 mg/dL) in the presence of other cardiovascular risk factors, including a positive family history of premature cardiovascular disease. Impaired flow mediated dilatation was more pronounced in FH children with a positive family history of premature cardiovascular disease. The currently prescribed diet is sometimes considered to be monotonous and can lead to problems with compliance. A reduction of the total intake fat and saturated fatty acids is important. Plant sterolesters should be evaluated in young FH children and can supplement drug and diet therapy, with an additional reduction of 10 to 15% of LDL-C. The use of resins leads to poor compliance, and statins are recommended for FH children and adolescents when drug treatment is indicated. Pravastatin, simvastatin, and atorvastatin decrease LDL-C 30 to 40% without serious adverse events and have a high degree of compliance.