The authors analysed the applicability of FISH on buccal and peripheral blood smears to detect Down syndrome among newborn infants. 11 children with previous cytogenetic result and 15 neonates examined prospectively were included in the study. All FISH results were in accordance with the cytogenetic diagnosis. In the prospective group the status of Down syndrome was confirmed in 12 cases, while 3 neonates turned to be healthy. Based on their preliminary results the authors emphasize the technique is extremely useful for a quick diagnosis especially when using blood smears. The method described here can be of a great help when there is no access to classical cytogenetic analysis, or it might fail to give result. Sample preparation is easy, microscopic slides with the specimen can be transported via regular post to cytogenetic laboratories.