The Prenatal Determinants of Schizophrenia (PDS) study was designed to examine early antecedents to schizophrenia. Based in the Child Health and Development Study cohort assembled in 1959-1967, over 12,000 cohort members were followed in the PDS study for psychiatric disorders. Using the extensive data and biological samples prospectively collected beginning during pregnancy, PDS investigators have examined the influence of prenatal exposures on risk of schizophrenia in adulthood. Here we describe a few key findings from the PDS with respect to prenatal infection, nutrition, and toxic exposures.