Background: Osteoporosis is one of the chronic diseases of the skeletal system characterized by low bone mineral density. Mouth saliva is made up of complex proteins and ions including calcium, potassium, and sodium. Since calcium is an important component of the skeletal system and exists also in saliva, in this study we examined the relationship between salivary calcium and osteoporosis. Methods: In this analytical cross-sectional study, unstimulated saliva samples were collected from 60 patients with rheumatoid arthritis who had history of steroid use. They were divided into equal groups of osteoporosis, osteopenia, and control. All data were analyzed using ANOVA statistical test in SPSS (v.18). Results: The average calcium concentration in groups of osteoporosis and osteopenia was 1.7 ± 0.70 and 1.7 ± 0.76, respectively. Also, the average frequency of dry mouth in osteoporosis and osteopenia groups was 5 and 6, respectively. The observed differences were not statistically significant between the groups (P = 0.4). Conclusions: According to the present study, there is no significant relationship between salivary and serum calcium and osteoporosis caused by treatment with glucocorticoid.