Background Rosacea is a chronic inflammatory disease which requires treatment to maintain remission. Objective Recently, the effect of Demodex mites in recurrence of rosacea has been described. Although there is limited data, previous reports have suggested that oral metronidazole demonstrated efficacy in treatment of rosacea. Methods Fifty-eight Korean patients with rosacea who received treatment with oral minocycline (50 mg twice daily) only or with two-week of oral metronidazole (250 mg thrice daily) were evaluated retrospectively. Their responses were evaluated by Investigator’s Global Assessment (IGA), Clinician’s Erythema Assessment (CEA), and patient’s Global Assessment. The recurrence rate and odds ratio of risk factors for recurrence were also estimated. Results The combination treatment group reported earlier clinical improvement and lower mean IGA and CEA than the monotherapy group. Approximately 48% of patients with combination treatment did not show relapse within 24 weeks, which is significantly higher than that in the monotherapy group ( p =0.042). Conclusion Add-on therapy of oral metronidazole appeared to be a significant protective factor for recurrence of rosacea ( p <0.05). This study suggests that oral metronidazole can be added to oral minocycline to reduce relapses in rosacea patients with tolerable safety.