Context: Non compliance is one of the main obstacles to an adequate control of the symptoms present in patients with schizophrenia. Objective: To review the reasons to treatment compliance and non compliance to drug treatment among patients with schizophrenia. Method: A comprehensive bibliographic review was performed (PubMed and Lilacs), includin papers that related compliance to drug treatment and schizophrenia. Results are presented in a short form to be more didactic. Results: Mean rates of compliance are reported between 50%. Main factors related to compliance, include socio-demographic variables, education level psychological profile of the patients, lack of insight, illness denial and perception of benefits from medication, relationship with the doctor and drug regimen complexity. It must also be taken into consideration the ways to detect and evaluate adherence degree as well as the means that can be used to improve compliance. Conclusion: Factors related to non compliance should be taken into account in all therapeutic planning.