Family members are important to the well-being of their relatives with substance use disorders or co-occurring substance use and mental disorders. Many caregivers experience high levels of burden, negatively impacting their capacity to provide support to their ill family member. The Andersen health care utilization model (Andersen & Newman, 1973, 2005) was used to identify the impact of predisposing, enabling and need factors hypothesized to predict caregivers' likelihood of asking for help and support with their caregiving role. The sample include 82 women recruited from outpatient or inpatient substance abuse treatment centers and 82 family caregivers nominated by these women. Findings showed that almost half of caregivers were unlikely to ask for help. Multiple regression analysis found that two need variables were statistically signficant predictors of caregivers' likelihood to ask for help. Caregivers who had higher subject burden (worry) and caregivers who provided more assistance with daily living were more likely to ask for help. It is suggested that case managers assess the amount of worried family caregivers' experience because their worries may provide the motivation to ask for help or to participate in help when it is offered to them.