Background Most pediatric venous thromboembolism (VTE) occur in children with at least one complex chronic condition (CCC) admitted to a tertiary care pediatric hospital (Setty et al, Pediatr Blood Cancer2012). Reports estimate 14.6%-29% of all inpatient childhood VTE occur in patients with chronic pediatric heart disease (CPHD) (Andrew et al, Blood 1994; Rafinni et al, Pediatrics 2009). The influence of acute VTE risk factors and the impact of non-cardiac CCCs on VTE in CPHD remain unknown. A large cohort of privately-insured children was used to evaluate the odds of VTE, estimate the healthcare burden, and delineate the risk factors associated with VTE diagnoses in CPHD. Methods Children Results There were 120,884 children 0-17 years of age with a CPHD diagnosis. VTE events occurred in 957 (0.79%) of these children, 802 (83.8%) of which were isolated DVT and 155 (16.2%) were PE with or without concomitant DVT. Male gender was significantly associated with VTE (P All CPHD were associated with a significant VTE risk except those with conduction disorders or dysrhythmias (Table 1). VTE occurred in 2.3% of children with single ventricle physiology, 1.9% of those with acquired CPHD, 1.6% with cardiomyopathy, and 0.5% with double ventricle physiology. Children who experienced VTE were significantly (P All measures of healthcare utilization (mean number of inpatient admissions (2.19 vs 0.62), mean inpatient length of stays (55.14 vs 8.7 days), mean number of outpatient visits (28.6 vs 11.22), and mean number of pharmaceutical claims (13.27vs 4.74)) were significantly higher (P Conclusions Although VTE in CPHD patients is rare, it does carry a significantly increased healthcare resource utilization and in-hospital mortality. All of the co-morbid conditions examined were significantly associated with VTE, but when controlling for non-cardiac CCC the odds of VTE was not affected. All of the non-cardiac CCC were significantly associated with VTE except malignancy and GI CCC when accounting for recent cardiac surgery. This suggests that non-cardiac CCCs may be an important determinant of VTE risk for children with CPHD. Disclosures No relevant conflicts of interest to declare.