Two siblings aged 18 months and 3 1/2 years with congenital chloride diarrhea are presented. This disease was first described by Gamble et al. and Darrow in 1945 and has not been observed to date in Switzerland. So far, 43 cases have been reported, half of them from Finland. The disease appears to be caused by an inborn defect of chloride transport across the mucous membranes of the distal ileum and colon. This defect leads to chronic liquid diarrhea. The clinical symptoms, diagnostic approach, and therapeutic problems and possibilities are discussed.