Background The long-term impact of childhood cancer treatment on dietary intake is likely to be complex and the length of time dietary behaviours are affected after childhood cancer treatment is unknown. Aim The aim of this study was to determine the diet quality in childhood cancer survivors recently off treatment and identify possible contributing factors that may affect diet quality in this population. Methods Participants were 65 parents and/or carers of childhood cancer survivors (CCS) (aged 2-18 years), recently off treatment and 81 age-matched controls. Methods Participants completed two self-administered dietary intake and eating behaviour questionnaires. Study data was explored to determine between group differences, bivariate analysis using Spearman’s correlations was used to determine the relationship between diet quality and identified variables, and hierarchical cluster analysis was completed to characterise specific variables into clusters. Results CCS had a significantly poorer diet quality score than the age-matched controls (t=-2.226, p=0.028). Childhood cancer survivors had significantly higher parent-reported rates of ‘picky eating’ behaviour than the control group (t=0.106 p=0.044). Factors such as picky eating, emotional overeating and Body Mass Index z-score appeared to drive diet quality in survivors. Conclusions A CCS with picky eating behaviours could avoid complete food groups, have strong food preferences/aversions and over- consume high energy foods to maintain their energy intake, possibly affecting diet quality. The outcomes highlighted the need for a tailored intervention aimed at improving healthy eating behaviours in CCS after treatment for cancer.