Aim: The aim of this study is to examine the effects of orally administered palmatine on periodontium in an experimental periodontitis (EP) rat model. Material and Method: A total of 40 rats were divided into 4 groups as group 1, no EP and no palmatine (CTRL); group 2, EP and no palmatine (EP); group 3, EP and 5mg/kg of palmatine (EP-5P); group 4, EP and 10mg/kg palmatine (EP-10P). Experimental periodontitis was achieved by plating 3.0 silk sutures on the cervical margins of the right mandibular first molar teeth of the rats. The alveolar bone loss, attachment loss and alveolar bone area were evaluated by histomorphometric evaluation. Immuno-histochemical evaluation was used to assess the Receptor activator of nuclear factor kappa-B ligand (RANKL) ve osteoprotegerin (OPG) immunoreactivity and RANKL/OPG ratio. Results: Alveolar bone area (ABA) values in palmatine groups were statistically higher than EP group (p<0.05). Alveolar bone level (ABL) and attachment level (AL) values were significantly lower in palmatine groups than EP group (p<0.05). For ABA, ABL and AL values, no significant difference was found between groups EP-5P and EP-10P (p>0.05). According to the RANKL / OPG ratio, a significant decrease was observed in the palmatine-treated groups during the experimental period (p<0.05). In addition, there was no significant difference between EP-5P and EP-10P according to RANKL/OPG ratio (p>0.05). Discussion: Palmatine might have protective effects on alveolar bone loss and connective tissue destruction in periodontal disease.