Purpose: To examine whether sterile water and brushes are necessary for hand washing before surgery. Method: Twenty-two operating room nurses were randomly divided into two groups as follows: 11 nurses who used 7.5% povidone iodine (PVI group) and another 11 nurses who used 4% chlorhexidine gluconate (CHG group) to wash their hands using the rubbing method. All the nurses were examined for bacterial contamination of their hands before and after surgical hand rubbing. We used tap water to wash the hands at the sink used for washing surgical instruments in the operating room and non sterilized plastic brushes. Results: No bacteria were detected in the tap water. Before washing the hands, the number of bacteria detected was 5.0×10³ cfu/H in the PVI group and 4.0×10³ cfu/H in the CHG group, which were similar in both groups. After washing the hands, the median value of the bacteria decreased to 8.7×10² cfu/H in the PVI group and 0 cfu/H in the CHG group. Conclusions: Sterile water and brushes are not necessary for preoperative scrubbing up. When using tap water for surgical hand washing, 1) the hand-rubbing method should be used; 2) a quick-alcohol-based disinfectant scrub should be used; 3) the concentration of free chloride in the water should be maintained at over 0.1 PPM; 4) the bacterial contamination of the water should be checked; and 5) the faucet should be routinely cleaned and sterilized.