This work aims at investigating the psycho-affective aspects of children with cancer, at Aldenora Bello Oncology Institute of Maranhão, and analyzing them as possible etiologic factors of the disease. It presents a theoretical reference about the importance of relationship between the children and their parents or references as children emotional, social and psychical support. It also addresses childhood cancer and its general characteristics. It presents a theoretical reference about the importance of the relationship between the children and their parents, characterizing it as a factor of children’s emotional and social development. It also addresses childhood cancer and its general characteristics. In the field survey, one took as a basis the results of individual semi-structured interviews with the companions of children undergoing treatment, in which one were investigated aspects such as: family dynamics, the parents-children relationship, childhood grief and children’s behavioral changes for becoming sick. There were children’s individual and group service, for assessment of their individual, family, and social life history. With the survey result, one intends to show that such psycho-affective aspects may be related to the uprising of the malignant neoplasia.