The seroprevalence of Toxoplasma gondii (T. gondii) antibodies in dogs in Maiduguri, the capital of Borno State, Nigeria, was determined using the Latex Aagglutination Test (LAT). Antibodies (LAT titer > 1:64) to T. gondii were found in 42 (25%) of the animals examined. Antibody titers in positive dogs ranged from 1:64 (15 dogs) to 1:2048 (3 dogs). There was a significant statistical difference (P < 0.05) between age groups of dogs, the prevalence being higher in dogs > or = 3 years (chi2 = 13.73 P = 0.0002, OR 2.80 CI95% 1.28-6.13 P = 0.008). Pure Alsatians and their crosses were less likely to be seropositive (OR cross breed 0.28 CI95% 0.13-0.61 P = 0.001, OR Alsatian 0.16 CI95% 0.04-0.58 P = 0.002). The high prevalence of T. gondii infection that we found in dogs suggests a need for a larger survey to determine the national prevalence and identify possible risk factors in different agro-climatic zones. Such a study will help in formulating nation-wide control measures for toxoplasmosis.