Introduction: Periodontitis is an inflammatory disease of the supporting tissues of the teeth that causes alveolar bone resorption. Aggregatibacter actinomycetemcomitans (Aa) is one factor that plays a role in the incidence of periodon- titis. Peanut shell (Arachis hypogaea L.) contains flavonoids such as luteolin, which affect an anti-inflammatory agent. This study aims to determine the effect of peanut shell extract on the number of osteoclasts in the alveolar bone of Wistar rats (Rattus norvegicus) induced by Aa bacteria. Methods: The research group consisted of 5 groups, and the negative control group was not given any treatment, while the positive control group and the treatment group were induced with Aa bacteria concentration of ±1x108 cells/ml for three weeks. The treatment group was further divided into three groups, and each group was also given ethanol extract of peanut shells orally at doses of 50 mg/kg BW, 100 mg/kg BW, and 200 mg/kg BW. Osteoclast cells in alveolar bone were counted from histological preparations of Hematoxylin-Eosin in rat mandible. Results: ANOVA analysis showed that the number of osteoclasts in the alveolar bone in the treatment group was significantly less (p<0.05) than the positive control group. Conclusion: Peanut shell ethanol extract significantly affected rat alveolar bone osteoclast cells induced by Aa bacteria.