Objective: As previous studies have shown, disabled children may prevent families to have their normal and desirable functions; hence, these families need to be supported. This study is trying to explore parental stress, satisfaction and family functioning of families who have children with autism and compare them with families with normally developing children. Method: This study is a casual-comparative and its statistical population included all mothers of children with autism and families with normally developing children in Tehran; 85 mothers of normally developing children and 58 mothers of children with autism were recruited using cluster sampling and convenience sampling method, respectively. The Parental Stress Scale (PSS) of Berry & Jones (1995), the Family Satisfaction Scale of Olson and Wilson (1986) and the Family Functioning Questionnaire of Olson et.al (1985) were used to gather the data. Results: Using multivariate analysis of variance (MANOVA), it was shown that there is a significant difference (P≥0.05) between parental stress, satisfaction and family functioning of families of children with autism and families with normally developing children. Conclusion: This study indicated that parental stress level of mothers of children with autism is more than that of parents with normally developing children and satisfaction and family functioning of their mothers are lower. This result may be due to the characteristics of these children, thus it is recommended to pay more attention to the health status of these families and support them more. Therefore, it was proposed that some programs to be designed to promote mental health of parents, especially in the centers for education and rehabilitation of mothers of children with autism.