Dry blood from mammals and birds was used as larval diet for the development of the cat flea, Ctenocephalides felis felis (Bouché), in the laboratory. Diets that contained host blood and cornmeal heated at 40 degrees C for 30 min were inadequate for most larvae to form pupae. Development time from 1st instar to adult ranged from 30 to 33 d. Except for the diet containing Mastomys blood, the diets that consisted of blood alone from other hosts air dried at room temperature contained sufficient nutritional value to allow adults to be obtained from > 51.7% of larvae fed these diets. Adults were obtained from > 81% of pupae. Although the Mastomys or mouse blood contributed to better diets than the dog or pigeon blood through shorter developmental time from 1st instar to adults, greater numbers of pupae and adults were obtained from diets that contained dog and mouse blood. Highly significant differences existed between pigeon and Mastomys blood in relation to the number of cocoons formed and between pigeon and dog blood or pigeon and mouse blood in relation to adult emergence. Differences between dog and mouse blood in the larval diet were significant only in relation to mortality that occurred to the pupae.