Objective: To examine the correlation of function, quality of life (QOL), and parental impact on developmental delayed children. Methods: Sixty parents of children with developmental delays ( M: F = 36:24, mean age 4 years and 2 months) and 56 parents of age-sex matched typical development children were included. Pediatric Outcomes Data Collection Instrument and Child Health Questionnaire for children, World Health Organization-QOL, Impact on Family Scale, and Hospital Anxiety and Depression Scale for parents were assessed. Results: Functional performance was correlated with physical component of QOL in children (correlation coefficients: 0.7-0.9; p < 0.01), age of children (0.3-0.4; p < 0.05) and parents (0.3; p < 0.05), maternal employment (0.3-0.4; p < 0.05), parental QOL (0.3-0.4; p < 0.01), family impact (−0.3 to −0.5; p < 0.01), and parental emotion (−0.3 to −0.4; p < 0.05). Conclusions: Children who exhibited higher levels of function had higher QOL, as did their parents, and less parental impact. [ABSTRACT FROM AUTHOR]