Summary: In a cohort of 310 consecutive congenital scoliosis patients, a retrospective analysis of abnormalities in ten organ systems was performed. Overall, intraspinal defects were observed in 43% of patients, and defects in other organ systems were found in 77% of patients. Urogenital anomalies occurred in 39% of patients. Cardiac anomalies occurred in 54% of patients, a rate more than two times higher than previously reported. The association between defects in various organ systems was also elucidated. Hypothesis: 1) The rate of cardiac anomalies in congenital scoliosis patients is higher than previously reported, 2) the presence of a single organ system anomaly increases the risk of further organ system anomalies. Design: Retrospective medical records review of databases from two tertiary-care pediatric hospitals. Introduction: Intraspinal, renal, cardiac, and gastrointestinal anomalies have been reported to occur at high rates in congenital scoliosis populations. No studies to date have identified associations among defects in various organ systems increasing the risk of further organ system anomalies. Methods: All patients diagnosed with congenital scoliosis that were <18 years of age at time of presentation with available MRI, renal ultrasound, or cardiac echo were included in this study. The incidence of defects in each organ system was analyzed. Results: There were 146 males and 164 females with a mean age of 7y 3.4m (0-18y). 83% of patients were observed to have at least 1 organ defect. 22% of patients had one organ defect, 19% had two defects, 18% had three, and 14% had four. An average of 2.2 total anomalies occurred per patient (range= 0-8). Intraspinal anomalies were observed in 43% of patients; syrinx occurred most frequently. Urogenital anomalies were observed in 39% of patients; solitary kidney was most prevalent. Cardiac anomalies were observed in 54% of patients; VSD was most common. In 12% of patients, a trio of spinal, urogenital, and cardiac defects was observed. Organ systems found to have significant associations (p<.05) in anomaly development are outlined in table 1. Conclusion: Cardiac anomalies were the most common defect in this study (54%), and occurred at a rate more than two times higher than previously reported. The high rate of intraspinal, urogenital, and cardiac defects makes MRI, renal ultrasound, and echocardiography a critical part of evaluation for all congenital scoliosis patients.