OBJECTIVE: To evaluate if there is any correlation between the growth rate of dominant follicles and clinical characteristics or outcome variables in women undergoing controlled ovarian hyperstimulation (COH). METHODS: This study was performed in 313 in vitro fertilization (IVF) cycles. Follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) were measured on day 3 of menstrual cycle, and serial ultrasonographic measurement of the diameter of growing follicles was performed. The growth rates of dominant follicles calculated by diameter difference divided by days were correlated with clinical characteristics and outcome variables. RESULTS: There was no significant difference in the growth rate of the dominant follicles between gonadotropin releasing hormone (GnRH) agonist and antagonist cycles. No significant correlation was found between the growth rates and evaluated factors such as age, body mass index, LH, FSH, E2, retrieved oocytes and fertilization rate. CONCLUSION: The Growth rate of dominant follicles seems to show an independent feature of basal characteristics and ovarian response.