Background & Aim: Hand scrub is used preoperative and invasive procedures.  It is the most important way for preventing of surgical wound infection.  But  the  frequent  use  of  scrub  contributes  to  skin  problems,  colonization  by  bacteria  and  change  in  normal  flora  presented  on  health  care  workers  hands.  That will increase rate of infection. The aim of this study was to determine surgical hand scrub duration on microorganism growth in operation room.
 
Material and Methods: This is a quasi experimental research. Sample consisted of 38 male and female fifth semesters and up baccalaureate nursing students that have been selected by simple sampling method. Al participants scrubbed for two minutes in the one stage and five minutes in the second stage. Then after scrubbing microbial specimens were collected immediately and one hour after scrub of their dominated hand. The instrument was a questionnaire and a data sheet for recording results of microbial cultures. The analytical methods Frequency, Means, Standard deviation, Chi –square, Fisher exact and Paired T- test.                             
                                     
Results: There was a statistically significant difference between means of colonies count immediate and one hour after two minutes scrub and five minute. Surgical hand times (p < 0.01). But no significant difference were found between means difference variation colonies count after two and five minutes   surgical hand scrub (p>0.05).
 
Conclusion: The findings indicate that two minutes surgical hand scrub is as effective as five minutes surgical hand scrub. So, two minutes scrub based on clinical usefulness is more effective than five minutes scrub.