The purpose of this study was to compare growth parameters of retinoblastoma patients with siblings and the normal Dutch population. Height, weight, head circumference and sitting height were measured in 67 patients and 63 controls. Target height was calculated based on the parental height of retinoblastoma patients. Standard deviation scores and population-based percentiles were calculated and used for statistical analysis. Retinoblastoma patients had larger head circumferences than the Dutch population and their siblings, and their weight was also higher than the Dutch population. Height and target height showed no differences from the Dutch population. Retinoblastoma patients had a greater sitting height than the Dutch population. Sample numbers were too small to reach statistical significance when comparing the sitting height of retinoblastoma patients with their siblings. No obvious explanations are available for these differences.