Diaper dermatit is among the widely seen inflamatory skin diseases in neonatals and small 0 -18 month old children. Control of causative agents as well as providing good genital care may prevent or reduce the risk of the disease. The aim of this study is find out the effect of protective genital care on reducing the diaper dermatit development in 0 -18 months old inpatient 0 -18 month old children who are using antibiotic. The study was conducted as prospective halfexperimetal using control-experimental groups. Our samples comprise of 0 -18 month old children admitted at Dokuz Eylul University Practical and Research Hospital, pediatric clinic between January and May 2009, 41 0 -18 month old children as a control group were not under protective genital care, and 42 0 -18 month old children as an experimental group were under the protecion and using vaseline. The mothers of the experimental group 0 -18 month old children were given education. All 0 -18 month old children were followed-up 3 -7 days and the collected data were evaluated in computer using Pearson's chisquare, Fisher's exact chi-square and Yatest-corrected chi-square tests. The diaper dermatit development ratio was 34.1% in the control group and 7.1% in the experimental group (p < 0.05). The rash disease in most of the control group 0 -18 month old children developed in 2 -3 days earlier than those in experimental group which appeared after the fourth day of study. All the 0 -18 month old children with diaper dermatit in the experimental group were found to be with first grade diaper dermatit while those with diaper dermatit in the control group were found to be with second and third grade diaper dermatit. The Diaper dermatit development ratio between the experiment group who were given the protective genital care and vaseline was meaningfully low in comparison to the control group who were not given any care.And those who acquired diaper dermatit disease among experiment group 0 -18 month old children the disease appeared in late days and was rather mild. As the diaper dermatit was found to be more frequent in 0 -18 month old children on antibiotics, to prevent the occurence of the disease proper protective genital care, vaseline use whenever the diaper is changed and giving education to mothers on the subject concerned is advised.