The aim of this research is to examine adherence, glycemic control and antihyperglycemic medication among individuals with schizophrenia and associated psychotic illnesses and a non-psychiatric control population. Methods: The medical records were reviewed retrospectively. Twenty-two diabetic patients with schizophrenia (31 patients with associated psychotic disorders, and 31 randomly chosen patients without psychiatric illnesses) getting medical care and psychiatric evaluation. Utilizing refill records from the system patient record , we calculated the cumulative mean gap ratio based on adherence to anti-hyperglycemic and anti-psychotic medication. To compare glycemic control between groups and to assess whether treatment guidelines for diabetes were meeting the glycemic goals, hemoglobin A1C values were utilized. Results: There were noticeable differences in adherence between the psychotic disorder group and the non-psychiatric comparison group when it came to anti-hyperglycemic medication, with approximately 65% of the psychotic disorder group missing antihyperglycemic medication for more than a month in the twelve month study period. Subject who adhere to their antipsychotic medications (80% adherent) were predominant to adhere to their antihyperglycemic medications (p=0.0003). Neither group differed significantly in glycemic control. Conclusion: Both groups had less than optimal adherence to antihyperglycemic medications and glycemic control. Psychotic patients and those without a mental illness did not show significant differences in adherence to antihyperglycemic medications and glycemic control