The aim of the study was to summarize the efficacy and tolerability of paliperidone palmitate, an atypical long-acting antipsychotic drug. Paliperidone is a 9-hydroxy metabolite of risperidone with a slightly different receptor profile and significantly different pharmacokinetic profile. After the short review of its pharmacological properties, the efficacy of the drug in comparison to placebo or to an active comparator was described. The studies revealed the effectiveness of paliperidone palmitate in the treatment of psychotic symptoms, mainly schizophrenia. The drug proved to be efficacious in both acute psychotic symptoms treatment and long-term treatment. Its efficacy in patients with schizophrenia was similar and sometimes even better than the efficacy of other long-acting drugs, such as risperidone or olanzapine. In the pharmacoeconomic studies, paliperidone proved to be cost-effective in comparison to risperidone or olanzapine. The review of the literature also underlined that paliperidone palmitate is well tolerated, compared with placebo. Frequency and severity of side-effects such as extrapyramidal symptoms, hyperprolactinemia and weight gain, was similar or less than those found in treatment with other atypical antipsychotics, including long-acting ones.