This paper show the investigation - intervention work based in a systemic - narrative - constructionist approach, about the familiar and personal narrative construction of the cancer experience in a minor son and his role in facing the disease in relation to the dynamic and familiar identity, in the interaction with the health context (Pediatric Oncohematology Service, La Misericordia Hospital of Bogotá) and the narrative cultural frame about the illness. Based on the assumption that the human experience is organized in narratives that people construct in the linguistic interaction with others, resarch was made with tree families with a minor son diagnosed with cancer, participating, along with the health team in charge, in conversational and reflexives sceneries that enabled to evoke, understand and to mobilize dominant narratives on the experience of the cancer that operated like obstacles in the process of familiar facing. It is identified in the narrative construction of the experience of the cancer, that the diagnosed and its negative implication in the familiar and personal life, was expirienced like an astonisher experience and confrontation. On the contrary, the identification and conversational construction of self-stories at familiar and personal identity level, facilitated the generation of alternating narratives which made possible the facing of the experienced situation. Key words: narrative, cancer, narrative construction of the familiar experience, familiar facing, Narrative systemic approach, investigation-intervention.