In Canada, atypical long-acting injectable (LAI) antipsychotics available for the treatment of schizophrenia or bipolar disorder include the following: risperidone, aripiprazole, paliperidone palmitate, and paliperidone extended-release. The purpose of this report is to evaluate the clinical effectiveness and cost-effectiveness, for the use of atypical injectable antipsychotics for patients with schizophrenia or bipolar disorder.