Acute eosinophilic pneumonia (AEP) is a severe syndrome which can be induced for many reasons, including drugs. AEP has rarely been associated with first-generation antipsychotics and never been reported after use of second–generation antipsychotics, such as risperidone. We report a case of a 64-year-old man with a medical history of alchoholism and paranoid symptoms, treated with risperidone at low doses. Following risperidone medication, he presented with respiratory distress. Bronchoalveolar lavage (BAL) specimen was indicated of AEP. All evidence indicated risperidone as the most probable causal factor. The syndrome rapidly resolved after discontinuation of the drug. Pathophysiological mechanisms implicated in the development of AEP in our patient seem to be associated with eotaxin and serotonin eosinophilic-specific chemoattracting action, through the serotoninergic action of risperidone. To our knowledge, this is the first case report of a clinical adverse reaction of AEP from an atypical antipsychotic agent (risperidone).