In the Department of Paediatric Surgery of the University Hospital of Mainz and the Department of Paediatric Surgery of the University Hospital of Frankfurt/M 90 children with thyroid gland lesions were operated on between 1970 and 1988. 78 patients had benign findings and 12 had malignant tumours. The most frequent operative indication for benign lesions was the euthyroid goitre (57 patients). We found nodular goitre in 45 patients, cystic goitre in 11 patients, and diffuse goitre in only 1 patient. 20 children were suffering from hyperthyroidism (11 with Basedow's disease, 9 with autonomy) and 1 from Hashimoto's thyroiditis. Among the malignant tumours, papillary carcinomas were the most frequent (5 patients), followed by follicular carcinomas (2 patients) and C-cell carcinomas (2 patients), and 1 case each of C-cell hyperplasia, retothelial sarcoma and malignant lymphoma. The following operative interventions were necessary: Among the patients with the benign findings, 28 unilateral subtotal resections were done (17 right side and 11 left side). 24 lesions were enucleated, 24 goitres were subjected to subtotal bilateral resection; in 1 case subtotal resection on the right side and hemithyroidectomy on the left side was performed, and in one patient polresection was necessary. All the 12 patients with malignant tumours underwent thyroidectomy: In 4 cases one-step operations were done and in other 8 cases multistep operations were performed.(ABSTRACT TRUNCATED AT 250 WORDS)