Objective To examine racial/ethnic disparities in quality of schizophrenia care and assess the size of observed disparities across states and over time. Data Sources Medicaid claims data from CA, FL, NY, and NC. Study Design Observational repeated cross‐sectional panel cohort study of white, black, and Latino fee‐for‐service adult beneficiaries with schizophrenia. Main outcome was the relationship of race/ethnicity and year with a composite measure of quality of schizophrenia care derived from 14 evidence‐based quality indicators. Principal Findings Quality was assessed for 325,373 twelve‐month person‐episodes between 2002 and 2008, corresponding to 123,496 Medicaid beneficiaries. In 2002, quality was lowest for blacks in all states. With the exception of FL, quality was lower for Latinos than whites. In CA, blacks had about 43 percent of the individual indicators met compared to 58 percent for whites. Quality improved annually for all groups in CA, NY, and NC. While in CA the improvement was slightly larger for Latinos, in FL quality improved for blacks but declined for Latinos and whites. Conclusions Quality of schizophrenia care is poor and racial/ethnic disparities exist among Medicaid beneficiaries from four states. The size of the disparities varied across the states, and most of the initial disparities were unchanged by 2008.