Information about the annual variation of trichomoniasis in mourning doves (Zenaida macroura) may be important in understanding mechanisms affecting mourning dove populations. The objectives of this study were to monitor the presence and annual variation of Trichomonas gallinae for 6 yr in a local mourning dove population using hunter-killed doves. During 1998–2003, 4052 hunter-killed doves were sampled for the presence of T. gallinae; 226 (5.6%) tested positive (4.4%–10.6% range). Results of the monitoring effort were relatively consistent during the 6-yr period, with the presence of T. gallinae being within the range of previously reported estimates for mourning doves. Asymptomatic carriers in one segment of the dove population may provide a mechanism for spreading the disease to other segments of the mourning dove population.