Using long-acting injectable (LAI) antipsychotic medications can improve the outcomes of patients with schizophrenia, such as reducing symptom severity and hospitalization risk. However, the outcomes of switching from oral to LAI antipsychotic medications are unclear. The purpose of this review is to provide a summary of the clinical, quality of life, and health care utilization outcomes of switching from oral to LAI antipsychotics among patients with Schizophrenia Spectrum Disorder. We thoroughly searched the PubMed, Scopus, PsycInfo, and CINAHL databases. To conduct the meta-analysis, we used the Comprehensive Meta-Analysis Program. Forty-one articles met our inclusion criteria. After switching to LAIs, symptom severity, the number of rehospitalizations, emergency department visits, and overall health care costs were reduced. Also, social functioning significantly improved. However, no differences were observed in the frequency of outpatient visits. Pharmacy costs were increased between pre- and post-LAI initiation. Our findings support evidence that changing the route of administration of antipsychotic medications from oral to long-acting intramuscular injections can improve the clinical, quality of life, and health care utilization outcomes in people with schizophrenia. Health care practitioners might consider encouraging LAI use earlier during treatment for schizophrenia for better clinical outcomes and to reduce health care utilization associated with treatment.