Introduction. Early diagnosis of FH is generally low. This leads to the early formation of atherosclerotic cardiovascular diseases (ACVD) and increases the risk of cardiovascular complications in young and middle-aged people. Aim. Identification of HeFH patients using the Dutch Lipid Clinic Network Criteria based on the analysis of electronic databases of two observational registries. Materials and methods. 3,895 persons were selected from 10,606 participants in the Duplex and Laboratory registries based on the presence of TC and LDL-C indicators registered in the databases and the criterion of age up to 60 years. Dutch Lipid Clinic Network Criteria (DCLN) were used as criteria for HeFH: “definite” in the presence of >8 points, “probable” in the presence of 6–8 points, “possible” FH in the presence of 3–5 points. The “definite” and “probable” groups were combined into “potential” FH group. Results. LDL-C levels ≥5 mmol/l and ≥6.5 mmol/l were detected in 8.7% and 0.7% of study participants, respectively. Among them, only 2 patients with DLCN criterion >8 points were identified. Potential FH was found in 13 patients. When recalculated per 100,000, the average prevalence of potential FH was 334/100,000 people (0.33%). Conclusions. Opportunistic screening is an affordable and effective tool in the hands of clinicians to optimize the detection of FH patients. It is advisable to use DCLN criteria, which are optimal as FH criteria. A well-proven method for analyzing electronic databases based on the study of electronic medical records, the use of a “potential” FH model and automated integration of the obtained data can significantly facilitate the task. Studies on larger cohorts of patients are needed to improve the detection of FH among young people.