Based on two surveys, the thesis focuses on the prevalence of filarial parasites of domestic carnivores in Gauteng, KwaZulu-Natal and Mpumalanga provinces in South Africa and Maputo province of Mozambique. This is complemented by diagnostic results of routine examinations for filarial infections of dogs and cats from South Africa obtained between 1994 and 2008. Blood samples were collected and initially screened by membrane filtration for microfilariae. Other techniques employed were acid phosphatase staining for the identification of microfilariae and a commercial enzymelinked immunosorbent assay for the detection of heartworm antigen. Combined with a critical literature review on filariosis of domestic carnivores in Africa, which is updated by diagnostic results obtained from animals in Africa between 1992 and 2008, the topic is addressed for the first time ever from a continental perspective. In the South African provinces and Maputo province of Mozambique 196 of 1 379 dogs (14.21 %) were found positive for microfilariae. The species identified were Dirofilaria immitis, Dirofilaria repens, Acanthocheilonema reconditum and Acanthocheilonema dracunculoides. The endemic status of D. immitis was confirmed in 2 out of 313 dogs from Maputo province but not in the South African provinces. Infection with D. repens was found in 70 dogs (5.08 %). The highest prevalence rate was recorded in KwaZulu-Natal with 12.47 % (52/417), followed by Maputo Province with 3.83 % (12/313) and Mpumalanga with 1.5 % (5/333). Routine examinations have also confirmed autochthonous infections with D. repens in Gauteng and North West provinces. Acanthocheilonema reconditum was the species with the highest overall prevalence of 8.85 % (122/1 379). The highest prevalence rate was recorded in Mpumalanga with 29.13 % (97/333) followed by Maputo province with 6.39 % (20/313) and KwaZulu-Natal with 1.2 % (5/417). Routine examinations have also confirmed autochthonous infections in Gauteng, North West and Western Cape provinces. Acanthocheilonema dracunculoides was the species with the lowest overall prevalence of 0.07 % (1/1 379) and was only recorded in 1 dog from Maputo Province. In KwaZulu-Natal 9 of 82 cats (10.98 %) were found positive for microfilariae, with D. repens as the only species involved.