The aim of this study was to evidence the clinical efficacy of an alcohol-free mouthwash containing 5.0% (W/V) Brazilian green propolis (MGP 5%) for the control of plaque and gingivitis. Twenty five subjects, men and women aging between 18 and 60 years old (35 ± 9), were included in a clinical trials phase II study who had a minimum of 20 sound natural teeth, a mean plaque index of at least 1.5 (PI), and a mean gingival index of at least 1.0 (GI). They were instructed to rinse with 10 mL of mouthwash test for 1 minute, immediately after brushing in the morning and at night. After 45 and 90 days using mouthwash, the results showed a significant reduction in plaque and in gingival index when compared to samples obtained in baseline. These reductions were at 24% and 40%, respectively (P < .5). There were no important side effects in soft and hard tissues of the mouth. In this study, the MGP 5% showed evidence of its efficacy in reducing PI and GI. However, it is necessary to perform a clinical trial, double-blind, randomized to validate such effectiveness.