Background. It is not known whether the management of multinodular goitre differs between endocrinologists and endocrine surgeons.Methods: A questionnaire containing a hypothetical case (a 42-year-old euthyroid woman with a 50-80-g multinodular goitre) and 11 variations on the case was sent to endocrinologists and endocrine surgeons in Australia.Results: The response rate was 55 per cent, including 45 endocrine surgeons and 127 endocrinologists. For the index case, serum thyroid-stimulating hormone (TSH), fine-needle aspiration biopsy and ultrasonography were widely used by both groups. Thyroid antibodies and scintigraphy were ordered by a greater proportion of endocrinologists than surgeons, and computed tomography more frequently by surgeons than endocrinologists. Treatment recommendations differed significantly between specialties for the index case (endocrinologists: no treatment 65 per cent, thyroxine 22 per cent, surgery 10 per cent, radioiodine 3 per cent; surgeons: no treatment 67 per cent, thyroxine 2 per cent, surgery 31 per cent; P < 0.001) and for seven of the variations. In particular, for a patient with suppressed TSH, most endocrinologists (60 per cent) recommended radioiodine treatment, whereas there was no consensus among surgeons (surgery 40 per cent, no treatment 36 per cent, radioiodine 21 per cent). For a patient with a partly intrathoracic goitre, most surgeons (88 per cent) recommended surgery, whereas there was no consensus among endocrinologists (surgery 45 per cent, no treatment 34 per cent, thyroxine treatment 13 per cent, radioiodine 8 per cent).Conclusion: There are clinically significant differences between endocrine surgeons and endocrinologists in the management of multinodular goitre.