We report a prospective study conducted from 1993 through 1995 in 846 patients (mainly women) consulting for a thyroid nodule. There were 465 multinodular goiters and 373 single nodules. The clinical diagnosis was obvious in 8 patients who were excluded. Pre-operative fine-needle aspiration was performed in 1235 patients and per-operative extemporaneous examinations in 569. These two simple reliable examinations, with few significant complications in skillful hands, are complementary. Fine-needle aspiration gives reliable histology data for thyroid nodules and should always be included in the pre-operative workup. Extemporaneous pathology examination of the surgical specimen provides information for adapted surgery and avoids morbidity due to reoperation.