Heteromultinodular goitres are frequent and the involutive forms require early surgical treatment for three reasons: these goitres are usually resistant to medical treatment; association with carcinoma is not uncommon (6.5% in this series); and the late surgery is hazardous, as it leads to extensive tissue resection and often entails a risk of recurrence and lesions of the parathyroid glands. Post-operative hormonal treatment should be reserved to those patients who have had wide tissue resection (replacement therapy for life, monitored by TSH assays) or to young patients who require a 2-year protective treatment. Prevention may perhaps be achieved by systematic 2-3 years' treatment of active homogenous hyperplasia in young subjects. Hyperplasia has a natural tendency to nodular involution, in most cases over several decades, but curiously, 30-35 years' old adults with large multinodular goitres are being operated upon as though these lesions had greater evolutive potential. This could be an argument in favour of post-operative protective therapy in these young patients.