The processes of rennet or acid coagulation of milk proteins are used while conventionally manufacturing cheeses, which are, as next, utilized in the production of processed cheeses. During those coagulation processes, valuable rennet proteins are removed since they are contained in whey being removed. One of the possibilities to include all milk proteins into processed cheeses is to use products obtained directly from milk concentrated by an ultra-filtration method. In this paper, it was investigated a possibility to use a specific yoghurt cheese, produced from an UF milk protein retentate, as a cheese base when manufacturing processed cheeses. A milk protein preparation (containing all milk proteins), i.e. the yoghurt cheese, was produced from a concentrated, 3.2% fatty milk; this milk was 5 times concentrated in a special ultrafiltration module. The retentate was pasteurized (72°C/15s), cooled to a temperature of 46 ± 2°C, mixed with the yoghurt bacteria culture inoculated, and packed in thermowelded plastic bags. The packed retentate was incubated in a temperature of 44 ± 2°C until its pH reached as level between 5,0 and 5,2; thereafter, it was cooled to a temperature of 6°C. The yoghurt cheese, manufactured using the method described, was utilized while manufacturing processed cheese; the latter was then standardized to a 55% water and a 55% fat content in its dry matter. To manufacture processed cheeses, the following ingredients were used: yoghurt cheese, Gouda-type rennet cheese (young and mature), butter, water, melting salts (Joha PL), and salt. Different amounts of the yoghurt cheese were added to the mixture being processed in order to achieve specific per cent proportion rates of the yoghurt cheese and other cheese ingredients, i.e.: 0%, 10%, 30%, 50%, 70%, and 100%. It was proved that the yoghurt cheese was a high quality, useful cheese base to manufacture a processed cheese which spread well, provided its content among all other components of the cheese mixture did not exceed 30%. If the addition of yoghurt cheese exceeded this level, the taste and flavor characteristics of a typical product usually manufactured from a mature, rennet cheese became milder. On the other hand, it was stated that with the increasing content of the yoghurt cheese, the pH value of the cheese mass decreased, but its hardness and apparent viscosity increased. It was proved that the yoghurt cheese could replace a non-mature rennet cheese, since its adventure was that it contained all milk proteins.