The objective of this study was to determine whether intranasal salmon calcitonin prevents physiological bone loss at perimenopause. A double-blind study of 120 perimenopausal women without present or past disease or medication that could affect bone metabolism were studied. The subjects were randomized in two groups and provided with nasal spray bottles containing either placebo (excipient only) or active compound (excipient plus 50 international units (IU) salmon calcitonin per dose). Subjects took one puff from the nasal spray in each nostril every morning. All subjects took one soluble tablet of calcium (1000 mg) per day. Serum biochemistry, dual-energy X-ray absorptiometry of lumbar spine and proximal femur, quantitative computed tomography of lumbar spine, and single photon attenuation of forearm were used to evaluate bone mineral density (BMD). There were no differences in demographic characteristics or hormone status at entry. No fractures were recorded during the study period. Serum calcium increased and serum dihydroxyvitamin D and osteocalcin decreased in both groups. There was no difference in biochemical parameters between the groups. The BMD of upper femur did not change during the study, but it was decreased in the lumbar spine in both groups. The mineral content of distal radius increased in both groups. In conclusion, nasal salmon calcitonin, 100 IU daily, has no protective effect on bone mass and does not modify bone metabolism at perimenopause.