Aim. To determine the relationships between trait anxiety, mothers' parental attitudes and functioning of children with Asperger's syndrome (AS) and verification of the hypothesis on the mediating role of parental attitude in relation between trait anxiety and AS child functioning. Method. The participants were 55 (mean age 39 years) mothers having one child with AS. The Polish adaptation of the State-Trait Anxiety Inventory, the Parental Attitudes Scale and the Child Difficulties Checklist were the measures used. Results. Correlation between trait anxiety and child functioning (difficulties intensity) was r = 0.47; p < 0.001. Four fifths parental attitudes considered in the study related to child functioning. Mothers' autonomous attitude correlated negatively (r = -0.28; p < 0.05), whereas demanding, inconsistent and protective attitudes were related positively (respectively r = 0.30, r = 0.33 i r = 0.52; ps < 0.05). Adopting regression analyses predictive value of parental attitudes was established and their mediating function tested. Conclusions. Trait anxiety relates positively to the extent of child difficulties and demanded support. Protective attitude is a significant predictor of AS child functioning and a mediator of the effect of trait anxiety on AS child functioning.