Purpose: To compare the oral health of patients with bipolar disorder (BD) with a control group of subjects. Materials and Methods: The study sample comprised 242 patients with BD and a mean age of 35.8 years. The control group comprised 187 subjects and a mean age of 37.3 years. Oral health was assessed through clinical examination by the Decayed, Missing, and Filled Teeth (DMFT) Index, the Community Periodontal Index (CPI), and the Simplified Oral Hygiene Index (OHI-S). Results: Patients with BD had higher caries prevalence, poorer periodontal health, and poorer oral hygiene than control group subjects. The average DMFT index score was 10.0 (SD = 5.7) in the BD group and 8.1 (SD = 5.2) in the control group (p = 0.002). The mean value of decayed teeth in patients with BD (4.5) was significantly higher than that of the control group (2.3) (p 0.001). Periodontal diseases were significantly more prevalent among patients with BD (p 0.001), particularly regarding shallow and deep pockets (47.1% vs. 16.6%). Oral dryness (xerostomia) and severe tooth wear were also more prevalent among patients with BD (p 0.001). Statistically significant risk factors for higher DMFT scores were: older age and having BD; CPI scores of 3 or 4; having BD, male gender, older age, and lower educational level. Conclusion: Poorer oral health among patients with BD is represented mostly as caries and advanced periodontal disease. The results of this study highlight the necessity to intensify preventive dentistry in this vulnerable population. Keywords: bipolar disorder, dental caries, periodontal disease, oral dryness, oral hygiene