This observational study assessed the influence of family support and substance abuse on patterns of service use by individuals with schizophrenia. Polychotomous logistic regression was used to analyze an existing database for 258 individuals with schizophrenia who were between the ages of 18 and 67 and were recruited from public mental health care settings. Analyses determined the extent to which two consumer-identified factors, family support and substance abuse status, influenced patterns of outpatient service use (regular, irregular, and infrequent) for schizophrenia. After the analysis adjusted for insight into illness, cognitive functioning, rural or urban residence, and gender, comorbid substance abuse and the interaction between substance abuse status and family support were significantly associated with patterns of service use. Comorbid substance abuse predicted irregular or infrequent patterns of service use over time. Stratified analyses indicated that weekly family support substantially reduced the adverse impact of substance abuse status on consumers' patterns of service use, especially for those living in rural areas. This study provides evidence that ongoing family support is associated with substantial reductions in the adverse impact of substance abuse on consumers' patterns of service use, especially for consumers living in rural areas. If confirmed in other populations, study findings suggest that reinforcing services and support for family members who provide informal care helps to sustain involvement in care by the especially vulnerable population of individuals with a dual diagnosis of schizophrenia and substance abuse.