Haemoproteus mesnili (Bouet 1909) Wenyon 1926 is redescribed from the spitting cobra, Naja nigricollis nigricollis, of Tanzania. Mature gametocytes in the acute phase of infection averaged 17.7 × 7.3 μm, with LW 128.1 μm², and L:W ratio 2.52. Nuclei were visible in both sexes. Both sexes were heavily pigmented, with 31–62 black granules dispersed in macrogametocytes; 20–46 granules were often clumped or concentrated near ends of microgametocytes. The halteridial form was present in 28% of active-phase gametocytes, but in only 8% of those in chronic phase. A few large, possibly first generation, meronts were present in cardiac muscle; uninucleate parasites within parasitophorous vacuoles in splenic cells produced small rounded or ovoid meronts, 12.2 × 9.6 μm, with 12–16 deeply basophilic, square-to-rectangular cytomeres. Meronts with 17–32 cytomeres were 16.9 × 11.9 μm. Meronts, 20 × 16 to 26 × 22 μm, contained 51–57 cytomeres. Mature meronts were ovoid, 13.7 × 11.5 μm, with many rounded merozoites. Haemoproteus balli n. sp, found in an Egyptian cobra, Naja haje haje of Kenya, differs from H. mesnili in average gametocyte dimensions, 10.8 × 7.7 μm; LW, 83.2 μm²; L/W ratio, 1.42; absence of halteridial forms; sparse pigmentation (3–10 granules); and presence of a broad peripheral band, apparently chromatin, along one side of microgametocytes.