Introduction: Children treated for cancer with a central venous catheter are often bothered by scarring. We studied whether glucocorticosteroid during patch occlusion has a beneficial effect on scar outcome in children and adolescents treated for neoplastic disease. Methods: A double-blinded placebo-controlled randomized clinical trial was performed. The main outcome was the Vancouver Scar Scale (VSS). Secondary outcomes were scar width and scar quality measured using the Patient and observer scar assessment (POSAS). The patients were divided into an intervention groups and a control group. The intervention group was randomized into two groups; Active and placebo group. The active treatment consisted of cream with glucocorticosteroid and fusidic acid. The placebo treatment consisted of cream with fusidic acid. Both groups were also treated with a silicone gel patch for three months after central venous catheter removal. The control group did not receive any specific skin care. Results: Assessment at 6 months were completed for 44 in the intervention group (21 in the active and 23 in the placebo group) and 47 in the comtrol group. The intervention group had a significantly lower VSS and a smaller scar compared to the control group (p = 0.00, p = 0.02). The POSAS by the patients and the study nurse showed no significant difference between the intervention and control groups (p = 0.84, p= 0.36). Conclusions: Silicone gel sheet alone or in combination with application of glucocorticosteroid during sheet occlusion improved scar outcome after removal of central venous catheter in children treated for neoplastic diseases.