Chronic generalized periodontitis (CGP) is a disease associated with low susceptibility to the therapeutic protocols applied; practitioners tend to characterize it as a disease presenting certain difficulties. Therefore, the search for drugs and methods capable of increasing the efficacy of CGP therapy is an ongoing process. Additional problems, which have to do with either with antibiotic resistance or increased sensitivity to drugs, also occur quite often. This study aimed to assess the possibility of applying hirudotherapy in the context of conservative treatment of CGP. 50 patients with CGP without somatic pathology were examined and treated. The participants were divided into two groups (n = 25), all group members of about the same age. At the first stage, the treatment followed the accepted standard: professional oral hygiene procedures, antimicrobial and anti-inflammatory drugs, demonstration of proper personal oral hygiene routines. Then, first group went through a monthlong hirudotherapy course that consisted of 6 to 8 individual procedures. Second group was observed throughout this period with the aim to control the level of their compliance with the oral hygiene routines they were trained. Having analyzed the results, we found that hirudotherapy was more effective than what was prescribed to the second (control) group. The papillary marginal alveolar index (PMA), which reflects the severity of inflammation and gum bleeding, decreased significantly in the first group, where medicinal leeches were used: in the patients with severe CGP it went down by 6%, in those with moderately severe CGP the index decreased by 24% and the participants whose CGP was only light had the PMA go down by 2%. Thus, we have demonstrated the efficacy of hirudotherapy in the context of conservative CGP treatment, which allows recommending this method for inclusion into clinical practice.