This patient complained of a swelling of the abdomen and vague pain. Ultrasound imaging of the pelvis showed a huge, cystic mass measuring 14 x 9 cms., with few septae traversing through it. No solid tissue was present within this cyst. The fluid within the cyst appeared to be clear serous type with scanty particulate matter within it. The kidneys appeared normal suggesting no pressure effects on the ureters despite the large size of the cystic tumor. The bladder was clearly identified separate from the cyst, thus ruling out a diverticulum of the bladder. Color Doppler image showed no significant vascularity in the septae. Final diagnosis from these ultrasound images was serous cystadenoma of ovary. With such large masses/ cysts it is not possible to determine the exact origin of the lesion/ or the side from which it originates.