This study was conducted in Meram district of Konya province (Turkey) in 2018 and 2019 to evaluate the efficacy of mating disruption against the tomato leafminer, Tuta absoluta in an open-field tomato growing area. Three pheromone-treated fields and three control fields were used to evaluate the effectiveness of mating disruption in both years. In pheromone-treated fields, mating disruption pheromone was applied once at a rate of 2500 g/ha with a caulking gun. In control fields, only pheromone traps were hung for monitoring and comparing the pest population. Male captures in monitoring pheromone traps and infestation rates of tomato plants by T. absoluta were recorded weekly. The mean number of males captured in the traps per week in pheromone-treated fields in 2018 and 2019 was 120.86 ± 16.82 and 69.90 ± 15.70, respectively. In control fields, the mean number of males captured in the traps per week in 2018 and 2019 was 299.73 ± 16.82 and 230.75 ± 15.70, respectively. The mean percentage of infestation of the pest was 4.40 ± 0.56% in pheromone-treated fields, while it was 11.80 ± 0.56% in control fields in 2018. In 2019, the mean percentage of infestation of the pest was recorded in pheromone-treated and control fields as 1.88 ± 0.52% and 7.39 ± 0.52%, respectively. As a result of the study, it was determined that the mating disruption application against T. absoluta was successful in all three pheromone-treated fields when compared to control fields in both years. This technique was tested for the first time against the tomato leafminer in Turkey with this project.