Halitosis is a major problem on social interactions in many people, and oral hygiene control is a major treatment for halitosis. However, medication may be the choice of method for non-oral origin halitosis. The present study evaluated the efficacy of chlorophyllin medication for oral malodor patients with GERD (gastroesophageal reflux disease). 26 patients with halitosis visited Department of Periodontology of Seoul National University Bundang Hospital. VSCs (Volatile Sulfur compounds) level was evaluated according to Chlorophyllin medication after 20 days’ medication. Scaling was conducted after medication, and VSCs level was measured 28 days after scaling. Chlorophyllin medication on the halitosis patients with GERD showed a statistically significant efficacy (P > 0.05). There was no significant effect on the patients without GERD (P>0.05). There was no significant effect s caling before o ne month ( P>0.05). Chlorophyllin was e ffective in t he halitosis patients with GERD. There was no significant difference one month after scaling.