A broad range of biological, genetic, environmental, and psychological risk factors for psychosis have been reported. Large-scale cohort studies using registry data are a reliable means of measuring the impact of these risk factors; however, previous studies employing this methodology have focused on a narrow range of variables. The aim of this study was to use data from a large birth cohort to examine the associations between ICD-10 psychotic diagnosis and a broad range of familial factors (advanced paternal age, family dissolution, parental psychosis), environmental factors (urbanicity, deprivation), psychological factors (childhood adversity) and gender. Data came from the Danish Civil Registration System and the Danish Psychiatric Central Register (N = 54,458). Multivariate binary logistic regression analysis indicated that five of the seven risk factors conferred unique risk for psychosis, with familial history and childhood adversity having the strongest effects. Overall, these findings indicate that familial, environmental and psychological risk factors confer unique risk for psychotic disorder.