Background: The aim of this study was to assess the dental status (DMFT) in patients with schizophrenia compared with a control group. Material: In this case-control study, 50 patients with schizophrenia attended in the Psychiatric Unit at the Virgen Macarena University Hospital of Seville were compared with 50 people (without systemic diseases and not taking psychotropic drugs) in a control group attended in the School of Dentistry of Seville. Decayed, missing and filled teeth (DMFT) were assessed according to the World Health Organization WHO criteria. Results: Patients with schizophrenia showed a decayed teeth (DT) score of 7.26 ± 5.69 compared with 6.50 ± 4.37 for patients the control group. These differences were significant and suggest that dental caries are most prevalent in patients with schizophrenia. People who smoked showed significantly higher DT scores in both groups. Among patients with schizophrenia, smokers scored 9.34 ± 5.42 compared with 4.38 ± 4.82 for non-smokers. Among the healthy controls, smokers scored 6.88 ± 4.85 compared with 6.12 ± 3.85 for non-smokers (p < 0.05). Patients with schizophrenia showed a missing teeth (MT) score of 9.10 ± 8.56 compared with 5.38 ± 5.14 in control patients. MT scores increased significantly with age and with smoking in both groups of patients (p < 0.05). Patients with schizophrenia showed a filled teeth (FT) score of 1.38 ± 2.70 compared with 2.34 ± 3.48 in control patients. FT differences in gender and smoking habits between patients with schizophrenia and healthy control subjects were statistically significant (p < 0.05). This data, along with the DT scores, suggests that patients with schizophrenia have extensive untreated dental disease. Conclusions: Patients with schizophrenia constitute a high risk population for dental health. This group showed a greater prevalence of decayed and missing teeth and more extensive treatment needs.