Abstract: Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), is a rare and highly aggressive ovarian malignancy associated with the SMARCA4 gene. It represents less than 0.01% of all ovarian tumors and primarily affects young women. This article presents a case of a 13-year-old girl with SCCOHT who exhibited abdominal distension and was found to have an abdominal and pelvic mass. Computed tomography (CT) revealed a large cystic-solid mass in the abdomen and pelvis with mixed density, progressive enhancement on contrast-enhanced scans, thickening of the ipsilateral ovarian artery, multiple enlarged lymph nodes along the greater curvature of the stomach and in the retroperitoneum, as well as ascites in the abdominal and pelvic cavities. Magnetic resonance imaging (MRI) demonstrated predominantly low signal intensity on T1-weighted imaging (T1WI), mixed high and low signals on T2-weighted imaging (T2WI), and markedly restricted diffusion of water molecules in the solid components on diffusion-weighted imaging (DWI). The postoperative pathological diagnosis confirmed SCCOHT of the right ovary. This article retrospectively analyzes the CT and MRI findings of this case, reviews the relevant literature, and summarizes key diagnostic points for SCCOHT to enhance understanding of this disease.