Background: Endometriosis is a gynecologic disorder which causes dysmenorrhea and infertility. Early diagnosis of endometriosis can help prevent the necessity for invasive diagnostic procedures. Medical imaging has been widely utilized to diagnose various diseases without the need for invasive procedures. The purpose of this study was to investigate the cervical length in women with endometriosis. Methods: In this case-control study, the case group consisted of nulliparous women with endometriosis, while the control group comprised nulliparous women without endometriosis. A total of 42 individuals were included in each group. Cervical length was measured using transvaginal ultrasound from the external os to the internal os. The patients in the case group underwent laparoscopy to confirm the diagnosis. Pearson chi-square test and Fisher’s exact test were employed to compare categorical variables with a p<0.05 considered statistically significant. Results: In both groups, there were no notable variations in any of the demographic characteristics. However, the severity of dysmenorrhea was significantly different between the two groups (p=0.01). The average diameter of the mediolateral cervix (29.48±6.2 and 27.14±3.8) was statistically significant between the patient group and control group, respectively (p=0.04). The mediolateral width may have a positive predictive effect on the presence of endometriosis, while cervical length appears to have a protective effect against endometriosis. Conclusion: Demographic data do not predict endometriosis. This study suggests that mediolateral width in transvaginal sonography can serve as a minimally invasive diagnostic tool for endometriosis, showing correlation with endometriosis symptoms like dysmenorrhea and dyspareunia.