Mothers of children with sensory-motor mental and chronic physical problems experience more stress than mothers of children with psychological disorders (P < 0.05). The stress score of mothers of children with psychological disorders was lower than the other two groups. Also there was a significant difference between the score of mothers of children with chronic physical problems and mothers of children with psychological disorders regarding parent-child dysfunctional interaction (P < 0.01). A significant difference was observed in terms of stress among mothers of children with sensory-motor mental problems with different number of children (P < 0.05); also mothers of children with chronic physical problems in different levels of education have experienced different levels of parenting stress (P < 0.05