Glucocorticoid and sex-steroid deprivation therapies are two major causes of medication-related osteoporosis. As clinical course of osteoporosis is rather chronic, other drugs for common chronic diseases could also affect the incidence of osteoporotic fracture. Peroxisome proliferator-activated receptor-γ agonist, loop diuretics, selective serotonin reuptake inhibitor, anticonvulsants and proton pump inhibitors are now considered to be important candidates as the cause of medication-related osteoporosis.