There has been a recent interest in calcitonin as a potential treatment for osteoarthritis, based on its metabolic activities in both bone turnover and cartilage. The aim of this study was to evaluate the effects of nasal form calcitonin on knee osteoarthritis and quality of life in women who receive calcitonin treatment for postmenopausal osteoporosis. Two hundred and twenty postmenopausal women, aged between 55 and 65 years with knee pain and knee osteoarthritis, graded II-III by using Kellgren-Lawrence radiographic scoring system, were included. Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, the quality of life questionnaire of the European Foundation for Osteoporosis (QALEFFO-41) and visual analog scale were used for the algofunctional assessments. Need of rescue analgesic was recorded. Pain (P < 0.001), stiffness (P < 0.05), functional capability (P < 0.05) and total score of WOMAC (P < 0.05) revealed statistically significant improvements after 3 months of the treatment and remained consistent throughout 1 year of the treatment period. Participants experienced significant reductions in WOMAC perceptions of pain (-53 %), joint stiffness (-44 %) and limitations in physical function (-49 %) at the end of 1 year of calcitonin treatment. Need of rescue analgesic intake was reported to have decreased approximately by 60 % at the end of the 1-year treatment period. QUALEFFO_41 scores improved: 37.6 (baseline), 30.9 (3 months), 28.0 (6 months) and 24.4 (1 year). In conclusion, nasal calcitonin treatment provided dual action on osteoporosis and osteoarthritis with significant improvements in quality of life and algofunctional results in knee osteoarthritis.