Aim: To investigate the effect of pretreatment with testosterone gel on IVF outcomes in patients with poor ovarian reserve. Materials and methods: In this prospective, single-blinded, randomized controlled trial, 87 patients, young or old (< or ≥35 years) with diminished ovarian reserve (DOR) (AFC ≤5, AMH ≤1.2 ng/mL) undergoing IVF treatment were enrolled and randomly divided into two groups. In the treatment group, 41 patients received pretreatment with testosterone gel (12.5 mg/day; from the 6th day of the previous menstrual cycle to 2nd day of stimulated cycle), and in the control group, 46 patients received lubricant gel. Results: Total number of oocytes retrieved (4.05 vs 2.72; p < 0.05) was significantly more in the treatment group than in the control group. Similarly, the number of grade A embryos (2.78 vs 1.96; p < 0.05) was significantly greater in the TTG group. The clinical pregnancy rate per patient was higher in the TTG group (37% vs 29.3%) but the difference was not statistically significant. Conclusion: Testosterone gel application before stimulation helps in reducing the dose and duration of gonadotrophins and to increase the number of oocytes retrieved and the quality of embryos formed in DOR patients. Clinical significance: Pretreatment with androgen before ovarian stimulation can be offered to patients with poor ovarian reserve.