The aim of the study was to evaluate vitamin A (Vit A) plasma levels in children with newly diagnosed neoplasia (NDN) admitted to the Department of Hematology-Oncology of G. Gaslini Institute. Vit A levels, retinol-binding protein (RBP), and nutritional status were evaluated in 54 children with NDN (22 solid tumors other than neuroblastoma, 16 neuroblastomas, 9 lymphomas, 7 acute lymphoblastic leukemia). Biochemical test results were also compared with those of 47 healthy controls (HC) comparable for sex and age. In children with NDN, mean Vit A plasma level results were 350 micrograms/L (95% CI 288-412); in HC they were 517 micrograms/L (95% CI 471-563), P < 0.001. Mean RBP value results were 3.2 mg/dL (95% CI 2.6-3.9) in NDN and 4.9 mg/dL in HC (95% CI 4.5-5.3), P < 0.001. Fifteen (28%) out of 54 children with NDN were classified as well-nourished, 27/54 (50%) were considered at risk of malnutrition, and 12 (22%) were malnourished. Children with NDN presented reduced Vit A and RBP mean values compared with those of HC. Further studies are needed to better evaluate Vit A metabolism in children with cancer at onset.