Familial Hypercholesterolemia is the most common hyperlipoproteinemia during the childhood, which occurs from the mutation of genes that regulates low-density lipoproteins (LDL), and is classified into two types, the homozygote presented abnormal genes from both parents and the heterozygote presented an abnormal gene from each parent. Type IIa familial hypercholesterolemia is characterized by, especially, increased level of LDL which is common type and normal level of high-density lipoproteins. The clinical signs are arterosclerosis, xanthoma of the Achilles tendons and the arcus cornea. The treatments are dietary and drug therapy. This report is a case of familial hypercholesterolemia diagnosed as type IIa hyperlipoproteinnemia with Insulin Dependent Diabetes Mellitus.