Breeding endangered species in captivity for reintroduction into their natural environment does not always yield the desired results. Despite significant financial and human resource input, adult birds and their offspring commonly die due to disease. This research compared the breeding success of capercaillies kept in breeding centre in relatively natural conditions and under strictly controlled, highly sanitary conditions between 1993 and 2020. The results showed that breeding under controlled conditions was more successful, with females laying, on average, more eggs (+3.4 eggs), hatching more chicks (+20.5%) and raising more offspring (+3.1 individuals). In addition, hatching success was higher (+ 13.18%) under capercaillie females than under foster parents (domestic hens). The percentage of chicks lost was higher (+14.82%) when incubated by domestic hens and reared without the involvement of capercaillie females. Controlled maintenance conditions thus led to significantly better breeding results (number of reared birds intended for release or sale to other facilities) and ensured the profitability of the breeding center.