The aim of this study was to compare the stability of mini-implants using drill-free and drilling methods, both before and after early force loading. Sixty-two adolescent patients (24 males and 38 females, mean age 15.7+/-4.2 years) were randomly assigned to three groups and 112 titanium mini-implants were placed between the upper first molars and second premolars to achieve molar distalization. Groups I (n = 22) and II (n = 20) received pilot drilling with diameters of 1.1 and 0.9 mm, respectively, while the drill-free method was used in group III (n = 20). Distalization forces of up to 200 g were applied with nickel-titanium (NiTi) open coil springs. The Z-test was used for statistical analyses to compare the success rates of the groups with each other.