Objectives: The purpose of this study was to identify the relationships between parenting stress, social support and parenting efficacy in mothers of children with disabilities. Methods: The subjects were 113 mothers of children with disabilities in G city. Data were collected using a structured questionnaire and analyzed by SPSS/PC+ 18.0. Results: There was significant relationship between parenting efficacy and social support (r=.21). But parenting efficacy was negatively correlated with parenting stress (r=-.48). The variables that affected parenting efficacy of mothers were parenting stress and social support. These two factors could explain 24.9% of parenting efficacy in mothers of children with disabilities. Conclusion: The study results show that parenting stress and social support influence parenting efficacy in mothers of children with disabilities. In order to increase parenting efficacy, the development of nursing intervention is needed and it can lead healthy life for mothers of children with disabilities.