4 mice were infected with chloroquine-resistant P. berghei. 5–7 days later tail blood and crushes of the organs were stained with Giemsa. The stage of development (trophozoite or schizont) and parasitaemia were determined for each slide. The schizonts concentrated in the liver, spleen and bone marrow and not in the heart, brain, lung and kidney. This organ distribution overlaps with that of P. coatneyi except for the paucity of schizonts in the heart of mice infected with chloroquine-resistant P. berghei. © 1969 Royal Society of Tropical Medicine and Hygiene.