BACKGROUND: According to most studies, the efficacy of IVF/ICSI protocols in patients with suboptimal response was significantly lower than in women with normal response. However, methodological approaches optimizing the efficacy of IVF/ICSI protocols in patients with suboptimal response have not been developed. AIM: The aim of this study was to evaluate the efficacy of using recombinant granulocyte colony-stimulating factor in IVF/ICSI protocols in women with predicted suboptimal response to controlled ovarian stimulation. MATERIALS AND METHODS: This prospective study included 102 patients with predicted suboptimal response: treatment group (n = 34) and comparison group (n = 68). Controlled ovarian stimulation was performed according to the standard protocol with gonadotropin-releasing hormone antagonists. Women in treatment group daily received 60 mcg of recombinant granulocyte colony-stimulating factor subcutaneously from the onset of stimulation until the day of human chorionic gonadotropin blood test. The intergroup comparative analysis included clinical-anamnestic data, indicators of hormonal status, ovarian reserve, main characteristics of protocols stimulation, embryological data and the efficacy of IVF/ICSI programs. RESULTS: In the treatment group, the number of retrieval oocytes was higher (8.1 ± 5.3 vs. 4.7 ± 2.6, respectively; p < 0.001), and the effective dose of follicle-stimulating hormone preparations was lower than in the comparison group (403.6 ± 351.1 IU vs. 694.3 ± 950.4 IU, respectively; p = 0.013). Besides, the number of mature oocytes (6.8 ± 5.2 vs. 3.7 ± 1.9, respectively; p < 0.01), 2PN zygotes (5.1 ± 3.9 vs. 2.8 ± 1.7, respectively; p < 0.01), and good quality embryos (3.4 ± 3.3 vs. 1.8 ± 1.5, respectively; p < 0.01) were also higher in the treatment group. Сlinical pregnancy rate in women receiving recombinant granulocyte colony-stimulating factor was significantly higher (41.2% vs. 22.1%, respectively; OR 2.47; 95% CI 1.01-6.03; p < 0.05). CONCLUSIONS: Using recombinant granulocyte colony-stimulating factor improves the efficacy of IVF/ICSI protocols in women with predicted suboptimal response.