This study has as objective to describe the experience of being mother of an autistic child. A qualitative approach was accomplished according to the phenomenological concepts of Martin Heidegger. Fourteen mothers of autistic children had been interviewed, with semi-structured questions, tape-recorded and transcribed integrally. The local of data collection was the AMA-PI with data produced in May, 2006. The analysis revealed that mothers who live the facticity of having an autistic child is permeated by negative feelings, faith and solitudeness. Mothers also leave their daily life to live their children's daily live. When assuming their existential condition - to be -in the world and to be mother of a autistic child, they begin to understand how to be capable to fight for their children's well-being, without complaints, demonstrating self-denial, patience and concern.