The effect of endocrine disorders on bone mass is being increasingly studied. It is suggested that the preceding thyroid disorder, rather than thyroxine replacement itself, may reduce bone mass. Fracture rate does not appear to be increased in primary hyperparathyroidism once the condition is diagnosed. Although osteopenia is widely accepted to be associated with diabetes mellitus, two studies report increased bone mass in this condition. However, diabetes appears to adversely affect bone formation and urinary calcium excretion. Osteopenia is not a problem in acromegaly despite that patients are often hypogonadal. The possible associations of thyroid disease with connective tissue disorders are discussed, and the role of androgens in the pathogenesis of connective tissue disease is debated.