Between 1974 and 1993 ten girls and six boys aged 6-16 years underwent total thyroidectomy, with therapeutic selective neck dissection in six patients. All were treated after operation with radioactive iodine (131I) for ablation of thyroid tissue remnants. Papillary carcinoma occurred in ten patients, follicular carcinoma in two and medullary thyroid lesions in four. The patients were followed for a median of 11.5 (range 1-20) years with regular determinations of serum thyroglobulin levels and 131I whole-body scanning when indicated. Only one patient had a slight increase in thyroglobulin levels without evidence of disease on further screening. In children with medullary lesions the serum levels of basal and pentagastrin-stimulated calcitonin remained normal. Currently all patients are alive and without disease. Hypocalcaemia lasting for more than 1 year was observed in one patient. Recurrent nerves were not injured accidentally, but because of tumour invasion two of 32 recurrent nerves had to be sacrificed. This surgical approach is safe and well tolerated in children.