The records of 506 patients with histologically proven nodular goitre treated by thyroidectomy between January 1966 and July 1988 were reviewed. There were 21 patients with thyroid carcinoma in nodular goitre giving a proportion of 4.1%. There was an almost equal ratio of papillary to follicular carcinomas in the patients with malignancy occurring in a multinodular goitre (11 papillary to 9 follicular). One had an anaplastic lesion. These patients had swelling for a longer period, 9.11 years, as compared with an average of 5.48 years for those with only nodular goitre (P = < 0.01) using the Student's t-test. The male to female ratio in those with multinodular goitre alone was 1:10.8 while in those with carcinoma in multinodular goitre was 1:3.2. Comparing these two groups, the odds ratio of malignancy among males was 2.82 (95% confidence limits of the odds ratio being 1.4-5.5). This indicates that males with multinodular goitre had a significantly higher chance of developing a malignancy, Chi-squared value 5.74 (P < 0.05).