In an effort to understand better the transmission risk as well for the animal African trypanosomosis (AAT) as for the human trypanosomosis (HAT) in the peri-urban zone of Kinshasa, a serologic study was carried out in local pig farms from 2003 to 2005. An indirect ELISA was used to detect the presence of trypanosome antibodies in 1,240 pigs originating from 404 farms. Seropositivity was recorded in 155 farms (38%), but varied considerably according to the district. In 6% of the farms TAA could be confirmed by parasitological examination. Trapping sites (n = 367) established in the neighbourhood of pig farms made it possible to capture 1,935 tsetse flies (Glossina fuscipes quanzensis). Among 562 dissected flies 23 were found to harbour trypanosomes resulting in an infection rate of 4.1%. In the majority of the districts the transmission risk for animal trypanosomosis anticipated from the apparent vector densities was corroborated by the serology. Zones with strong indications of local AAT transmission were identified in several quarters of three peri-urban districts of Kinshasa: Mount-Ngafula, Ngaliema and N'Sele. An intensification of tsetse control activities in those sites of increased transmission risk is essential.