Cystic fibrosis (CF) is the most common fatal autosomal recessive multisystem disorder, which occurs mainly in European-derived populations. The incidence of CF varies between 1 in 2000 to 3000 live-births in various ethnic groups. The disease is rare in East Asians. Here we report a 9 year old Thai male patient, who was diagnosed to have CF based on recurrent pneumonia, a slow weight gain, pancreatic insufficiency and repeatedly elevated sweat chloride levels by two different methods. A comprehensive genetic analysis showed the splicing mutation, 1898+ 1G-->T, which was apparently of maternal origin. Literature search found 39 documented cases of CF patients in East Asians. CFTR (MIM# 602421) genotyping was performed in 14 patients including our patient and in 9 of them a CF allele was identified. The findings seem to indicate that the splicing mutations, 1898+ 1G-->T and 1898+ 5G-->T are more common in East Asian CF patients.