The socio-communicative adjustments of children with autism spectrum disorders (ASD) are assumed to be altered by their poor psychological understanding. However, their performance in theory of mind (ToM) experimental tasks doesn't always reflect their difficulties to adapt in everyday life. More ecological measures are thus needed to capture how ASD children cope with Tom-laden situations. This paper presents functional analyses comparing typical and ASD children in two communicative situations that potentially elicit ToM capacities: (1) the negotiation of disagreements during spontaneous family interactions; (2) a narrative eliciting task. Participants were autistic children and their family members (part 1) and Asperger children (part 2) aged between 5 and 11 years. They were compared to typical children matched on verbal age. Data collection: (1) For each family, one hour of spontaneous videotaped home interaction was systematically coded for oppositional episodes, including justifications, until their resolution; (2) Children produced narratives based on a series of wordless pictures depicting events open to mentalistic causal explanations. Stories were transcribed and coded for psychological references. In both studies, similarities between ASD children and matched controls on some measures and specific differences on others appeared: (1) disagreements in home interactions occurred with the same mean frequency and sequence length. In both groups, the justification of first oppositional moves reduced the probability of the partner's insistence. The effect was stronger in children with lower rather than higher verbal levels, while the latter tended to counter-argue more. However, ASD children with verbal age of 3-4 years justify their disagreements significantly less than controls; (2) Asperger children, although producing narratives of equivalent linguistic form, referred less to mental states and had difficulty in integrating them in causal frames. The discussion will examine the cost of using cognitive resources in communicative contexts and its impact on the socio-pragmatic functioning of ASD children.