Background It has been recently suggested that second-generation antipsychotic long-acting injection (SGA-LAIs) are underutilized in clinical practice, despite that their costs significantly impact on national health system budgets. Hence, an updated analysis of safety data shown by SGA-LAIs may contribute to clarify their role in clinical practice. Materials and methods English-language, peer-reviewed articles reporting updated, primary findings on the SGA-LAI safety were identified (updated through an electronic search of five databases – PubMed, EMBASE, PsycInfo, DARE and the Cochrane Library). Results The articles reviewed suggest that the most frequent treatment emergent adverse events (TEAEs) associated with aripiprazole long-acting injection (ARI-LAI) are psychotic symptoms, extrapyramidal symptoms (EPS) and weight gain. Data on olanzapine long-acting injection (OLA-LAI)-associated TEAEs highlight the risk of psychosis, metabolic disturbances and hyperprolactinemia. Four-hundred and forty cases of post-injection delirium/sedation syndrome (PDSS) have also been recorded. Although not reported in reviewed studies, the risk of impulse-control problem and drug reaction with eosinophilia and systemic symptoms (DRESS) ARI- and OLA-associated, respectively, must not be underestimated. With regards paliperidone palmitate 1-month formulation (PP1), the high incidence of clinically relevant weight gain and hyperprolactinemia are both findings of concern. Reviewed data also confirm that the leading cause of death in risperidone long-acting injection (RIS-LAI) clinical trials is suicide. The new 3-month paliperidone palmitate formulation, risperidone sustained release 1-month formulation (RIS-SR1), aripiprazole lauroxil (ARI-LXL) are still lacking exhaustive safety data. Conclusion The risk of specific TEAEs associated with all SGA-LAIs confirms SGA-LAIs do not offer advantages in safety compared with FGA-LAIs or oral antipsychotics and, especially, in early-phase schizophrenia patients. Implementing non pharmacological intervention and strategies can be effective for people with schizophrenia and bipolar disorder who adhere poorly to medication regimens.