Fanconi anemia (FA) patients suffer from progressive bone marrow failure and often develop cancers. Previous studies showed that antioxidants tempol and resveratrol (RV) delayed tumor onset and reduced hematologic defects in FA murine models, respectively. Here we tested whether antioxidants N-acetylcysteine (NAC) or RV could delay cancer in tumor prone Fancd2−/−/Trp53+/− mice. Unlike tempol, neither compound had any significant chemopreventive effect in this model. We conclude that not all anti-oxidants are chemopreventive in FA. In addition, when given to Fancd2−/− mice, NAC helped maintain Fancd2−/− KSL cells in quiescence while tempol did not. The mechanisms behind the different actions of these antioxidants await further investigation. Pediatr Blood Cancer 2014;61:740–742. © 2013 Wiley Periodicals, Inc.