The aim of the overview is to show the distribution of common apolipoprotein E (APOE) genotypes in the Croatian population, and to test whether it could serve as a new molecular biomarker in some clinical entities. The study included the following groups: patients with angiographically confirmed coronary artery disease, myocardial infarction, Alzheimer's dementia, vascular dementia, hyperlipidemias, diabetes mellitus, pancreatitis, and healthy subjects. Group comparisons of different clinical entities and control group were performed using Pearson's Chi2-test. There was no difference in APOE genotype frequencies between coronary artery disease neither myocardial infarction and control group. The ApoE genotype frequencies in patients with Alzheimer's disease were significantly different from those in the control group. APOE-4 allele tends to be a risk factor for the development of Alzheimer's disease. The frequencies were only marginally different in vascular dementia. Patients with hypercholesterolemia, those with inherited familial hypercholesterolemia, children with diabetes mellitus, and patients with pancreatitis of different etiology showed distributions of APOE genotypes that differed from the control group. It is concluded that the frequencies of APOE genotypes yielded no statistically significant result to confirm the association between APOE genotypes and any specific disease with the exception of Alzheimer's disease; APO-epsilon4 allell has become one of the important biomarkers in diagnosis of Alzheimer's dementia.