Over the last decade increasing number of enteritis cases have been attributed to infection with a new coccidian sp that was named Cyclospora cayetanensis in 1993. Diarrhoea caused by this agent is clinically indistinguishable from cryptosporidiasis, isosporiasis and microsporidiasis but cyclospora infection are often very prolonged (upto 15 weeks) and may cause severe weight loss. Diagnosis is important because unlike diarrhoea caused by cryptosporidium and microsporidium, treatment with co-trimoxazole is effective. We report here a case of cyclosporiasis, to increase awareness of possibility of cyclospora infection in patients with prolonged diarrhoea. It should be considered in assessment of patients with unexplained prolonged diarrhoeal illness.