Granulosa cell tumours (GCTs) account for less than 3% of all ovarian malignancies but are among the most common sex cord-stromal tumours. They may develop at any age. Symptoms related to oestrogen production by the tumour may occur. Because GCTs are uncommon and cannot be diagnosed preoperatively, their management is challenging. Surgery with salpingo-oophorectomy and painstaking staging is mandatory. Adjuvant chemotherapy is required in some patients. We report two cases of adult GCTs that illustrate the usefulness of extensive abdominal exploration in every patient with a suspicious ovarian mass, to obviate the need for a second staging procedure. With this strategy, the prognosis is excellent, although the possibility of late recurrences requires prolonged follow-up.