This is a non-randomized, single-arm, multi-center (conducted in more than one center) study to explore response to treatment and safety of flexible dose of paliperidone extended-release (ER) in participants with schizophrenia. During the study period, dose of paliperidone ER will remain within the range of 3 to 12 milligram per day and will be administered for 12 months. Both hospitalized and non-hospitalized participants may be included in the study. Participants may switch to any effective dose of paliperidone ER from any oral antipsychotic medication without dose adjustment or if required, cross-dose adjustment may be done. Maximum 4 weeks of switching period is allowed. Use of anticholinergic (opposing the actions of the acetylcholine, a neurotransmitter) drugs will not be restricted. Response to treatment will be evaluated primarily through total Personal and Social Performance (PSP) Scale. Participants' safety will be monitored throughout the study.