One of the most common oral manifestations of menopause is xerostomia. As gingival tissue is sensitive to changes in the female sex steroids; the aim of this study was to evaluate the relationship between saliva 17β-estradiol and severity of xerostomia. A case-control study was carried out in 64 selected menopausal women aged 42-75 years with or without xerostomia (32 as case and 32 as control) conducted at the Clinic of Oral Medicine, Tehran university of medical sciences. Xerostomia inventory (XI) score was used as an index of xerostomia severity. The saliva 17β-estradiol was measured by an enzyme immunoassay kit. The mean unstimulated saliva flow rate and concentration of 17β-estradiol were significantly lower in case than control. There were significant negative correlation between XI score and unstimulated whole saliva flow rate and also concentration of 17β-estradiol in menopausal women. It seems that there is a negative correlation between xerostomia severity and saliva 17β-estradiol in menopausal women.