Several types of tissues (lung, kidney, bone marrow, and skin) from 2 subhuman primate species, the rhesus macaque and the African green monkey, were used to initiate primary cultures and propagated in vitro to determine the feasibility of the establishment of "longterm" diploid cell lines.. Most skin lines can be propagated for over 40 subculture generations (passages) and maintain a chromosome constitution like that of the primary cultures. Instead of reliance on a single cell source such as the WI-38 line, more diploid cell lines from human and subhuman primate sources should be made available for biomedical research and for pUblic health work.