Latino families have been reported to underutilize health care services compared with families from other ethnic backgrounds. As part of a community trial in a low income Latino population designed to decrease environmental tobacco smoke (ETS) exposure in children with asthma in San Diego, we examined unscheduled medical care for asthma. Latino families (N = 193) reported information about medical care use for their children during the past 12 months. About 23% were hospitalized, 45% used the emergency department, and 60% used urgent care services. About 8.5% of families had two or more hospitalizations in 12 months. Most families were insured by Medicaid or had no insurance. Significant risk factors for a child's hospitalization were age (under age six), failure to use a controller medication, and a parental report of the child's health status as being poor. Risk factors for emergency department use were age (under age six) and male gender. These findings indicate that low-income Latino families with young children with asthma lack the medical resources necessary for good asthma control. Quality and monitored health care with optimization of asthma management could reduce costly acute care services.