Despite the worldwide importance of zoonotic parasite Toxoplasma gondii, nothing is known of toxoplasmosis in animals in Angola. The present study aimed at estimating the seroprevalence and also at assessing correlates of T. gondii infection in pet dogs from Luanda, Angola. Dogs (n = 103) brought to a veterinary clinic in the city of Luanda were investigated. Serum samples were tested for antibodies to T. gondii with a modified agglutination test (MAT) commercial kit, at serial dilutions of 1∶20 to 1∶160. In accordance with the established cutoff value (MAT ≧20), 16 dogs [15.5%; 95% confidence interval (CI): 9.2–24.0%] had antibodies to T. gondii: 10 had a titer of 20, two had a titer of 40, and four had a titer of 80. Age (≧12 months) was found to be a risk factor for infection [odds ratio (OR) = 9.23; 95% CI: 1.16–73.27). For each 1-year increase in age, the risk of a dog being found seropositive significantly increased by an OR of 1.18 (95% CI: 1.02–1.36). The present study, which represents the first serological survey of T. gondii in any animal species from Angola, reveals a 15.5% seroprevalence of infection in pet dogs in Luanda. Further studies are needed to better understand the epidemiology of zoonotic T. gondii infection in Luanda and also in Angola.