Purpose <p>To evaluate the impact of poor ovarian response (POR) on live birth outcomes in endometriosis patients undergoing IVF/ICSI-ET, despite the expected association between reduced oocyte yield and poorer prognosis.</p> Methods <p>Patients were divided into two groups as endometriosis group (<i>n</i> = 55) and tubal factor group (<i>n</i> = 107). The primary outcomes included clinical pregnancy rate, live birth rate per embryo transfer cycle, and cumulative live birth rate. Secondary outcomes were controlled ovarian hyperstimulation (COH) results and embryo parameters.</p> Results <p>The incidence rate of POR increased significantly in endometriosis group (18.9% vs. 5.60%, <i>P</i> &lt; 0.05). Similarly, the number of oocytes retrieved, the number of D3 high quality embryos, and the number of available embryos were fewer in endometriosis group (<i>P</i> &lt; 0.05). However, total number of available embryos, clinical pregnancy rates per transfer cycle, live birth rates per transfer cycle, and cumulative birth rate were found to be similar in both groups (<i>P</i> &gt; 0.05). The presence of POR was found to have no significant impact on the cumulative live birth rate among patients with endometriosis.</p> Conclusions <p>While linked to fewer oocytes per cycle, POR does not predict poorer IVF/ICSI-ET outcomes in endometriosis patients. Patient age, not POR or endometriosis itself, is the primary determinant of live birth success. This study challenges the conventional emphasis on oocyte quantity, advocating for a paradigm shift toward individualized, quality-focused ART strategies in endometriosis-related infertility.</p>