The first time we started our epidemiological studies of mucopolysaccharidoses lysosomal diseases in the population of Azerbaijan Republic. Each suspicious patient in mucopolysaccharidoses lysosomal diseases underwent medical genetic consultation, glucoseaminglycans were analysed in the urine with thin-layer chromatography, relative lysosomal enzyme activities were analyzed in blood serum. Gene level diagnostics were done by means of Sanger sequencing and New Generation Sequencing genetic methodiques. Altogether there 947 genetically affected patients and their family members from 29 out of 86 economic regions of the country. Mucopolysaccharidosis affected 34 patients (homozygotes) and 89 heterozygotes were identified. Patients were checked up for all five types of mucopolysaccharidoses: Hurler (MPS I), Hunter (MPS II), Sanfilippo (MPS III), Morquio (MPS IV), Maroteaux-Lamy (MPS VI). Phenotypic and gene frequencies of mucopolysaccharidoses were counted. The lowest frequency was evaluated for Hurler syndrome (5,9%), then came Maroteaux-Lamy syndrome (7,7%). The highest frequency among all identified MPS syndromes - around half of them (50%) - was for Morquio syndrome. MPS IVA/MPS IVB ratio was 16:1. Hurler and Sanfilippo syndromes had frequencies as high as 14,7% and 20,6%. The Republic population mucopolysaccharidoses phenotypic frequencies were presented with comparison to populations of countries and continents. Based on the obtained practical and scientific results the ways for prophylaxis would be developed, designed and implemented for families with genetic risk of mucopolysaccharidoses.