Purpose: To evaluate the efficacy and safety of orthokeratology in patients with low and medium myopia. Material and Method: Twenty six eyes of 6 male and 7 female patients were evaluated prospectively. The mean spherical equivalent was -3.87±1.35 D (-7 - -2.25) in 26 eyes. Individual semi-rigid, gas-permeable night Gelflex lenses (Australia) were performed based on keratometry values, ambient pupil, mesopic pupil, and autorefractometry values providing best-corrected visual acuity (BCVA). In all cases, uncorrected and best-corrected visual acuity, refraction, keratometry, corneal topography, slit lamp and intraocular pressure measurements were evaluated on first day, at first week, and at first, third and sixth months. Results: While the mean uncorrected visual acuity (UCVA) before orthokeratology (Ortho-K) was 1.08±0.24 (0.4-1.3) logMAR, first week after Ortho-K, it was 0.24±0.27 (0-1) logMAR. The BCVA was 0.01±0.07 (0-0.4) logMAR prior and first week after Ortho-K. First week after Ortho-K, it was 0.22 logMAR at right and 1 logMAR at left. While the average UCVA of our cases at first month was 0.11±0.19 (0-0.8) logMAR, the average BCVA at first month was 0.018±0.08 (0-0.4) logMAR. No ophthalmological complications were noted. Discussion: Ortho-K is a safe and effective method for correction of low and moderate myopia in patients who do not prefer surgery and do not wish to wear glasses or contact lenses during the day.