 This is a randomized patients assigned to treatment groups by chance, double-blind patient and study staff will not know the treatment assignment study of paliperidone palmitate compared with RISPERDAL CONSTA Risperidone Long-Acting Intramuscular Injection in adult patients with schizophrenia. The total duration of the study will be approximately 14 weeks. For those patients without source documentation of tolerability to oral by mouth risperidone or paliperidone Extended Release ER tablets, injectable RISPERDAL CONSTA or paliperidone palmitate, or those patients who were not currently taking another antipsychotic, a minimum of 4 days and a maximum of 6 days of oral paliperidone ER treatment at a dosage of 6 mgday will be administered for tolerability testing before the first injection of double-blind DB study drug paliperidone palmitate or RISPERDAL CONSTA. During the DB period, study drug will be administered to patients as an intramuscular i.m. injection. Paliperidone palmitate PP 150mg equivalent eq and RISPERDAL CONSTA placebo at Baseline BL Day 1, 100mg eq at Visit V 4 Day 8, 50 or 100mg eq at V7 Day 36, and 50,100,or 150mg eq at V9 Day 64 or RISPERDAL CONSTA RC 25mg at V4 and V6 Day 22, 25 or 37.5mg at V7, and 25, 37.5, or 50mg at V9 will be given as i.m. injections. Patients in the RC group will also take risperidone tablets 1-6 mgday at BL for 28 days and be given an injection of PP placebo at BL, V1, V7, and V9. 