AbstractNoonan Syndrome (NS) is a common genetic disease with multiple organ defects including bleeding disorders, which was last reviewed in 1997. Since then significant information has been acquired regarding bleeding problems in NS, specifically on the underlying genetics. Associations between mutated genes and bleeding disorders are reviewed along with prevalence and underlying etiologies. Between 50–89% of NS patients will have a bleeding disorder and since a significant number will require surgery it is important to identify which ones are at risk prior to their procedure. Recommendations regarding screening for bleeding disorders and their treatment are discussed. Pediatr Blood Cancer 2012; 58: 167–172. © 2011 Wiley Periodicals, Inc.