During the period from May to September 1987 stools from 200 children (aged 2 months to 4 years) with diarrhoea at Children's Hospital in Havana City were tested for enteropathogens. Three stool samples collected from each patient on alternative days were examined for Cryptosporidium oocysts by direct wet mounts, concentration by the method of Ritchie (formol-ether sedimentation) and by modified Ziehl-Neelsen staining technique. Total prevalence of intestinal parasitoses was as high as 24.5%. Cryptosporidium infection was found in 8% (16 children). Cryptosporidium was the second most commonly detected enteric pathogen overall after Lamblia intestinalis (identified in 10%). In the overwhelming majority of patients Cryptosporidium was the only detectable pathogen (13 cases of monoinfection). In the youngest children Cryptosporidium was the commonest parasite. It is noteworthy that all children who excreted the Cryptosporidium oocysts were exclusively bottle-fed.