Fifteen percent (81 of 542) of striped skunks, Mephitis mephitis, collected in the prairie of Alberta and Saskatchewan during 1974 to 1978, were positive for antibodies against Toxoplasma gondii. The seropositive rates varied from 8% (6 of 78) for skunks less than six months of age to 47% (9 of 19) in animals three or more years old. Spring and summer transmission was indicated by a preponderance of high titres (greater than or equal to 1:1024) in seropositive skunks collected April through September (22 of 40, 55%) compared to seropositives collected October through MFarch (10 of 38, 26%) (P = < 0.05). Prevalence was significantly greater among skunks collected in the relatively humid parkland (63 of 286, 22%) than in the arid prairie grassland biome (20 of 225, 8%) (P = < 0.01). The results indicate that T. gondii is focally enzootic in Alberta and Saskatchewan.