This paper presents the results from analyses of water samples from 15 Bulgarian reservoirs and lakes for detection of microcystins presence by high-performance liquid chromatography (HPLC) coupled to a ultraviolet (UV) and photo diode array (PDA) detector. In 3 of the studied drinking water reservoirs cyanobacterial blooms were not detected. Cyanobacterial blooms were observed in 6 of 12 investigated water bodies used for fishing and water sports. Microcystis was the dominant cyanobacterial genus. The concentration of total microcystins in the biomasses ranged from 8 to 1070 lg g -1 (d.w.). Microcystin-LR and microcystin-RR were the predominant microcystins, followed by microcystin-YR. Presence of dissolved microcystins was obtained in one water sample with concentration of total microcystins 1.64 lg L -1. Presence of microcystin-LF and -LW or unknown peaks possessing characteristic microcystin-like UV-spectra were not detected. Those first results for occurrence of microcystins in some Bulgarian reservoirs and lakes are a contribution to the knowledge on their distribution.