The reasons for time clock use in health-care institutions, the categories of workers required to use a time clock and other timekeeping methods, and the incidence of time-clock-related conflicts were studied. A questionnaire was mailed to a random sample of 565 hospitals in October 1989. Usable responses were received from 340 (60.0%) of the institutions. Reasons given for time clock use included payroll tabulation, overtime calculation, and ensuring fair payment. Thirty-four institutions (10.0%) required all employees to clock in, and 179 (52.6%) required some employees to do so. A written time card completed by the employee was the method used most frequently if a time clock was not used. Clinical pharmacists were required to clock in at 51 institutions (15.0%), staff pharmacists at 62 (18.2%), and pharmacy technicians at 144 (42.9%). Clinical nurse specialists and registered nurses clocked in at 88 (25.9%) and 169 (49.7%) hospitals, respectively, and licensed practical nurses and nurse's aides each clocked in at 176 hospitals (51.8%). Less than 6% of the hospitals required salaried pharmacists or nurses to use a time clock. Of the respondents, 152 (44.7%) reported that they were not aware of any conflicts or that no conflicts had been experienced. Inconvenience and inaccurate clocking were the most common sources of conflict cited. Most hospitals use time clocks for nonsalaried employees for bookkeeping purposes; dissatisfaction with this method of tracking hours worked does not appear to be widespread.