Purpose: To assess the efficacy of a mouthwash containing 2% green tea as compared to a placebo mouthwash for the control of plaque and gingivitis. Materials and Methods: A randomised controlled clinical trial was conducted on 110 male subjects 18-60 years of age. The inclusion criteria were having a minimum of 20 sound natural teeth, a plaque index (PI) of at least 1.5 and a gingival index (GI) of at least 1.0. The subjects were randomised into two parallel groups, test and control. Subjects in the test group and control group were instructed to rinse twice daily for 1 min with 10 ml of test (mouthwash containing 2% green tea) and placebo mouthwash, respectively. After 28 days of using the mouthwash, inter- and intragroup differences for mean plaque index and gingival index scores were analysed. Results: There was a significant (p 0.05) reduction in mean GI and PI scores among the test group from baseline to 28 days, whereas it was not significant in the control group. A statistically significant (p 0.05) reduction was found in the mean difference in GI scores in the test group (0.67 ± 0.22) as compared to the control group (0.05 ± 0.11) and a statistically significant (p 0.05) reduction was observed in the mean difference in PI scores in the test group (1.65 ± 0.68) compared to the control group (0.45 ± 0.99). Conclusion: The results showed that the green tea mouthwash was effective in the reduction of plaque and gingivitis scores. Keywords: gingival index, green tea, mouthwash, plaque index, randomised controlled trial