Transvaginal ultrasound (TVUS) uses a specially designed endocavitary transducer inserted into the vaginal canal to image the uterus, ovaries, fallopian tubes, and early gestational contents at close range. Because the probe is immediately adjacent to the pelvic organs, high frequencies can be used, providing superior resolution compared to transabdominal imaging. TVUS is the preferred method for evaluating early pregnancy, endometrial pathology, ovarian cysts, and pelvic pain, and is a core skill for OB/GYN sonographers.