Chronic interstitial cystitis (IC), mostly affecting middle-aged women, is a very rare manifestation of primary Sjogren's syndrome (pSS). Hereby, we report a 42-year-old woman with pSS, presenting with dysuria, urinary frequency, and suprapubic pain. She was diagnosed to have chronic IC, based upon the cystoscopic biopsy finding of chronic inflammation in the bladder wall. Systemic corticosteroid and azathioprine treatments together with local intravesical therapies were not effective. Therefore, cyclosporine (CSA) therapy was initiated. Initial low dose of CSA (1.5 mg/kg/d) improved the symptoms of the patient, with no requirement for dose increment. After 4 months of therapy, control cystoscopic biopsy showed that bladder inflammation regressed and IC improved. This case suggests that even low doses of CSA may be beneficial for treating chronic IC associated with pSS syndrome.