Background: Treatment non adherence in patients with schizophrenia is the main reason for frequent relapses, poor treatment outcome, reduced quality of life and significant increases in healthcare cost. Objectives: This study was conducted to determine the prevalence of treatment non adherence in patients with schizophrenia and identify factors associated with it. Method: One hundred and twenty patients with schizophrenia receiving treatment in the mental health unit were randomly selected to participate in the study. Data were collected using a socio-demographic questionnaire, the 8-item Morisky medication adherence scale (MMAS-8), Drug attitude inventory (DAI-10), Positive and Negative Symptoms Scale (PANSS). Logistic regression was used to determine significant variables associated with suboptimal adherence to medication. Results: The prevalence of treatment non-adherence was 51.7%. The factors significantly associated with treatment non adherence were a poor attitude to medication (OR 0.067, 95% CI0. 012-0.387, P-value 0.03) lack of supervised treatment (OR 0.117, 95% CI 0.038-0.352, P-value< 0.001) experience of side effects (OR 4.40, 95% CI= 1.358-14.313 p-value 0.01). Cost of medication (OR 3.867, 95% CI 1.232-12.136) and a high negative PANSS score (t=-1.91, P value 0.04) Conclusion: Adherence to antipsychotic medications among patients with schizophrenia is suboptimal. The findings strongly recommend the need to develop a standard protocol for carrying out adherence counselling to all patients and their relatives.