Two epidemiological surveys of cryptosporidiosis in urban and suburban areas of Libreville, Gabon, Equatorial Africa, were conducted in children. On 450 fecal samples on the first study, Cryptosporidium sp. has been seen about 3.11%. For the second survey, on 296 children, aged between 0 and 2 years, with acute diarrhoea, the rate of infestation was 24%. The maxima was observed for infants aged between 6-18 months, in case of malnutrition and during wet seasons.