Background: This research was planned with the aim of determining the effect of symptom frequency of children with cancer on the quality of life of their parents. Materials and Methods: In gathering the research data, the Child and Parent Information Form, the Symptom Evaluation Form and the Family Version of Life Quality Scale in Cancer Patients were used. Evaluation was made by using percentage calculations, Kruskal Wallis test, Bonferroni adjusted t-test and Bonferroni adjusted Mann-Whitney U test. The significance level was accepted as 0.005. Results: Some 37.6% of the participant children were female and 62.4% were male, with an average age of $10.2{pm}4.5$. While 41.0% were newly diagnosed, 46.2% were in remission and 12.8% was in relapse. Highly significant differences were detected according to the symptom frequency with parent physical and psychological health, social anxiety, and spiritual wellness sub-dimensions, as well as total point averages. Conclusions: It is thought that following up the symptoms that might develop depending on cancer diagnosis and treatment and implementing nursing initiatives aimed at reducing the symptoms, knowing the importance of life quality, maintaining measures aimed at life quality and planning initiatives to increase the life quality will play a key role in maintaining and developing the health of Turkish paediatric oncology patients and their parents.