The literature is reviewed on three family risk indicators that have prognostic significance in schizophrenia: expressed emotion, affective style, and communication deviance, each measured in key relatives of schizophrenia patients. Expressed emotion and affective style have been used primarily to characterize family environments that predispose patients to psychotic relapses. Communication deviance has been used primarily to distinguish the communication styles of families of schizophrenia patients from those of families without schizophrenia. Data on the roles of genetic, biological, and psychosocial factors in the origins of these family attributes are reviewed. Although studies of family risk indicators have yielded relatively consistent cross-sectional and longitudinal findings, much remains to be clarified about what these constructs actually measure and their mechanisms of prediction. The implications of family risk research for prevention efforts are discussed.