Background: Asthma is the most common non-communicable disease among children and the prevalence of childhood asthma is increasing in Vietnam. Often, due to the stage of development of the child and the illness, control of asthma in pre-school age children depends on family caregivers. To design effective interventions for asthma control, understanding family caregivers' perceptions of factors that influence such control is necessary. Thus, this cross-sectional study developed and tested a model of how perceived social support, satisfaction with nursing care, access to healthcare and family management work to explain asthma control among pre-school age children. Methods: A convenience sample of 328 primary family caregivers of pre-school age children with asthma from three public hospitals in Da Nang, Vietnam was recruited. Questionnaires used were a demographic form, and Vietnamese versions of the Best Asthma Control Test for Preschoolers, the Modified Social Support Questionnaire, the Access to Healthcare Instrument, and the Patient Satisfaction with Nursing Care Quality Questionnaire. The SPSS version 18 and the AMOS program were used to test the model. Results: Findings revealed that the hypothesized model fitted with the data and explained 38% of the variance in asthma control. Contextual factors had a direct effect on asthma control and an indirect through family management. Family management had a significant direct positive effect on asthma control. Among these factors, perceived social support had the strongest total effect whereas access to health care had the strongest direct effect on asthma control. Conclusion: Nurses can use this finding to strengthening support from significant people to improve family management and strengthen access to health care using various strategies such as telehealth to support asthma control.