The microbiological evaluation of technological process of frozen string-bean was done and its sanitary condition during 3 month storage in -18°C was controlled. Following parameters were determined: total plate count, yeasts and moulds, coliform bacteria, Salmonella and Listeria, enterococci and anaerobic bacteria. In string-bean taken from raw material transporter a high level of contamination with bacteria (10⁷-10⁸ cfu/g) and with yeasts and moulds (10³— 10⁴ cfu/g) respectively was found. In the same samples coliform bacteria were present in 10^-2-10^-3 g, enterococci in 10^-3— 10^-5 g and anaerobes in ≥10^-2 g. Salmonella and Listeria were not found in 25 g in any sample. Only blanching process turned out to be essential for lowering the microbiological contamination of string-bean in which the total number of microorganisms was lowered to 10 cfu/g, yeasts and moulds to 10²—10³ cfu/g; enterococci were present in 10^-3-10⁴ g and anaerobes in 10^-1 g. Coliform bacteria were present on unchanged level in 10^-3-10³ g. After 3 month cold storage of string-bean in -18°C the lower level of bacteria was observed but the number of moulds and yeasts reminded on the same level as just after freezing.