Introduction: Germ cell tumours of the ovary are rare ovarian tumours. The degree of malignancy differs between the different histological types. Materials and methods: Our study is a retrospective descriptive and analytical survey carried out in Sousse over a period of 21 years and involving 30 cases. Objectives: To analyse the particularities of malignant germ cell tumours of the ovary. Results: The mean age of our patients was 22 years. The average consultation time was less than 6 months. The reason for consultation was abdomino-pelvic pain. Abdominopelvic ultrasound showed a heterogeneous echogenic mass. Lymph node surgery was performed in only 10% of our patients. Stage I was predominant in 17 patients. Complementary treatment to surgery in the form of poly-chemotherapy was indicated in 24 patients. Mean survival was 94 months. CONCLUSION: Surgery plays a major role in the management of malignant germ cell tumours of the ovary.