The duration of handwashing was studied in two community hospitals (teaching and nonteaching). The duration in seconds of 180 handwashes by health care personnel and 52 handwashes by non-health care personnel were recorded. The mean duration for health care personnel was 8.62 +/- 0.29 SEM; the degree of patient contact did not influence the duration of handwashing. The duration of handwashing was two times longer in health care personnel vs. non-health care personnel (8.62 +/- 0.29 vs. 4.14 +/- 0.42; t = 7.7; p less than 0.001). Comparisons revealed no statistically significant difference in duration between personnel at teaching and nonteaching hospitals or among those in different occupations. The data indicate that the duration of handwashing among health care personnel is below the standard recommended by authorities in hospital infection control. This may be an important factor in the transmission and persistence of nosocomial infection in critical care units. The antimicrobial efficacy of handwashing agents should be reevaluated considering the actual duration of handwashing by health care personnel within the hospital environment or efforts should be made to increase the duration of handwashing.