OBJECTIVES This descriptive study aimed to assess parental knowledge regarding cancer-related symptoms and their attitude regarding fatigue in children treated for cancer. METHODS This study included 89 parents of children with cancer who were being treated in the pediatric oncology clinics of four hospitals in Izmir. A questionnaire form consisting of 13 items was used to collect data. RESULTS Parents observed severe alopecia in 48.3%, fatigue in 49.4%, nausea-vomiting in 34.8%, anxiety in 24.7%, moderate taste change in 23.6%; constipation/diarrhea in 28.1%, pain in 7%, sleeping difficulty in 12.4%, and rare respiratory distress in 7.9%. Parents reported cancer-related fatigue severely affecting their children's school activity in 43.8%, friendships in 39.3%, psychology in 37.1%, play activity in 36%, energy in 29.2%, and family relationships in 28.1%. CONCLUSION We determined that parents were able to assess their child's cancer-related symptoms, as well as the fatigue that affected their child's quality of life.