After different methods of hand preparation, volunteers rolled segments of sterile central venous catheter between their fingertips, and bacterial transfer was evaluated by standardized quantitative culture. The number of bacteria transferred differed between methods (P<0.001). Comparisons were made with the control group (no preparation at all; median, third quartile and maximum count=6.5, 24, 55). Bacterial transfer was greatly increased with wet hands (1227, 1932, 3254; P<0.001). It was reduced with a new rapid method, based on thorough drying with a combination of 10 s using a cloth towel followed by either 10 or 20 s with a hot-air towel (0, 3, 7 and 0, 4, 30, respectively; P=0.007 and 0.004, respectively). When asked to follow their personal routines, 10 consultant anaesthetists used a range of methods. Collectively, these were not significantly better than control (7.5, 15, 55; P=0.73), and neither was an air towel alone (2.5, 15, 80; P=0.176) nor the hospital's standard procedure (0, 1, 500; P=0.035). If hand preparation is needed, an adequate and validated method should be used, together with thorough hand drying.