Paliperidone is a second-generation antipsychotic used in the treatment of Schizophrenia. It is also available as Paliperidone Palmitate (PP), a long-acting injection that can be administered monthly (PP1M) or every 3 months (PP3M). To our knowledge, only one case of PP accidental overdose has been described in Literature. We report a 55-year-old male who accidentally received a cumulative dose of 200 mg of PP within 5 days. The mistake was promptly recognized and this allowed a careful follow-up over the following hours and days. Clinical evaluation, supported by blood and instrumental tests, showed no medical consequences and the patient never complained of side effects. No additional therapy was required. Our experience, supported by data from the literature, suggests that PP is generally well tolerated and safe. However, a close clinical follow-up during the hours and days following an accidental overdose is recommended.