Conventional methods used in laboratory animals for collection of resident macrophages (MAC) proved suitable for isolation of hepatic, splenic, dermic, peritoneal and alveolar MAC of healthy dogs. Phagocytic assays of IgG opsonised SRBC were performed with resident MAC obtained from these organs. Results showed the existence of statistically significant differences among phagocytic capacity of the investigated MAC. According to this, three groups of MAC could be defined: a first group comprising dermic, splenic and alveolar MAC; a second group comprising hepatic MAC and a third group comprising peritoneal MAC.