This observational study measured waiting times, appointment durations, and scheduling variables of a single family practice physician. Waiting time and appointment duration in four sequential groups of sessions were compared using analysis of variance; each group used different scheduling templates. Groups 1 and 2 used a 15-minute base interval; group 3 used a 20-minute base interval. Observations for group 4 were collected at a different health center using a 15-minute base interval. Scheduling variables were correlated with waiting time using correlation coefficients, and data were collected on 1783 appointments. The best waiting time (mean +/- SD) was 17.33 +/- 19.19 minutes. The mean appointment duration for this group was 17.99 +/- 7.97 minutes. The F statistic comparing the four groups of sessions for waiting times was 34.14 and for appointment duration was 37.37, both of which are significant (P < 0.001). The Spearman correlation coefficient for waiting time with queue was 0.2474 (P < 0.001). The Spearman correlation coefficients for mean waiting time and lateness of starting a session (0.4530), patients per hour (0.3461), and patients per session (0.3674) were all significant (P < 0.001). Both scheduling and patient flow affect patient waiting times. The best schedule would consist of shorter sessions that started on time and were extended to accommodate extra patients rather than adding in patients and crowding the schedule. In addition to reducing the actual waiting times, the perception of waiting can be managed to minimize patient dissatisfaction.