The aim of this study is to investigate the efficency of the standard surgical hand washing process using 5 minute time procedure, against gr(-) & gr(+) bacteriae at operation room nurse's hands. This study had done in medical school of Cerrahpa~a, University of Istanbul.This study is done by semi experimental. Before the study, 40 operation room nurses that included the study had performed educational program for one week ago. And standard written educational forms had given to them. At the two step investigation the gr (-) & gr ( +) bacteria colonies taken from the hands of each nurses had studied. The data were interpreted by hisdeded Wilcoxon m11tched, Mc Nemar, Mann-Whitney U and Kruskal Wallis tests. Finally of the study; it is found that the operation room nurses had been looking for the increase at time of study in operation room is seen to affect the handwashing behavior positively. The use of the warm water at surgical handwash is being detected more effective than use of cold water in decreasing the number of gr(-) & gr(+) colonies of bacteriae. Also it had been found that the number of colony of the gr(-) & gr(+) bac teriae decreases 64.7 %-69.4 % after five minute surgical hand washing including brushing of the nails and washing through 3-5 cm above the elbow with disposable sponge-brush combination including 7 .5% PYI.