This is an open-label (all people know the identity of the intervention), multi-centric (conducted in more than one center) and non-comparative study of long-acting risperidone in participants with schizophrenia who have a previous history (in the last 12 months) of bad adherence to the oral antipsychotic treatment of first or second generation. The duration of this study will be 24 weeks and will include following visits: Screening, Baseline, Week 2, 4, 8, 12, 16, 20, 24, 38 and 50 (End visit or early withdrawal). All the eligible participants (after risperidone intolerance test during screening) will receive a dose of 25 milligram risperidone every two weeks by intramuscular injection (injection of a substance into a muscle). Efficacy and safety of the participants will primarily be evaluated by Positive and Negative Syndromes Scale and Extrapyramidal Symptom Rating Scale, respectively. Participants' safety will be monitored throughout the study.