Thirty early postmenopausal women having risk factors for osteoporosis entered and 23 completed a six months double-blind placebo controlled study of the effect of nasal salmon calcitonin (SCT) (100 IU daily) plus oral calcium on bone turnover, cortical bone mass and sex-steroids. After the double-blind study SCT treatment was continued for six months in 20 women in both groups. A six months nasal SCT treatment was found to be effective in significantly increasing cortical bone mass and the gain was maintained following a 12 months treatment. The nasal SCT treatment was effective in significantly reducing parameters of bone turnover, as indicated by osteocalcin pBGP and urinary hydroxyproline levels, while during placebo administration an increasing trend of pBGP suggested a state of increasing bone remodeling. During the study, a small decrease in plasma testosterone not related to cortical bone mass and bone turnover was observed.