A series of bacteriological analyses of water collected from distributors applied to dose water from containers of more than 5 litres volume. The objective of the laboratory studies was to determine the washing and disinfection efficiency with regard to a special type of the system used. Water samples were collected after the completed cleaning and disinfection of the distributors. Water in the bottle and a distributor constitute one integral unit offered to customers. Thus, the final water quality is, in fact, influenced by the two factors: purity of water in the container and distributor’s cleanness. With regard to the structure of the distributors, they can be divided into two types. The first type comprises distributors, in which the exchange of the elements directly contacting water is easy to perform, and the second type: devices in which the replacement of spare parts is impossible. A parameter called evaluation efficiency of the cleaning and disinfection procedures was set. It was proved that some differences in the structure of the distributors determine the selection of an efficient disinfection method. Distributors of the first type were disinfected once, and after this treatment they distributed water of no microbiological changes. As for the distributors of the second class, it was necessary to disinfect them twice in order to obtain the same effect as the single disinfection treatment of the first class distributors. 99 distributors of the second class, out of totally 308 distributors checked, needed to be disinfected for the second time because water from them contained coli bacteria (Psudomonas aeruginosa). The investigation performed shows that the method of washing and disinfecting distributors depends on the structure of the distributors.