Goitre is endemic in mountainous northern and north western areas of Pakistan. The most important hazard of goitre is the presence of cancer. At AFIP, Rawalpindi, thyroid cancer accounts for about 9 percent of the malignant tumours. Malignancy should be suspected in a nodular goitre when the nodule is discrete particularly in a young patient. Definitive diagnosis depends upon histological examination. A suspicious nodule should be excised completely for biopsy. It should never be incised. A clear appreciation of the natural history of the different histological types is essential for correct management of the disease. In particular, the subdivision of papillary carcinoma into occult, intrathyroidal and extrathyroidal tumours, and of follicular carcinoma into noninvasive tumours, is of vital importance in prognosis.