Objective: Infants with "single ventricle" congenital heart disease are at high risk for sudden death following palliative surgical management. We developed a pilot telemedicine project to evaluate the feasibility of using Web-based daily reporting of clinical data with the goal of reducing unexpected admissions and sudden death., Subjects and Methods: We enrolled 9 subjects (enrolled subjects [ES]) following surgical palliation over 12 months. Parents electronically transmitted ES daily weight and oxygen saturation and then completed an automated 10-point phone questionnaire on nutrition, activity, and distress. Subject enrollment continued until a second surgical palliative procedure (n=5), sudden death (n=2), or disenrollment (n=2). We collected clinical data on all ES and 9 historical controls (HC) from the preceding 18 months and analyzed clinical management, including outpatient telephone surveillance success, scheduled and unscheduled office and emergency department visits, hospitalizations, procedures, and adverse events, including death., Results: Subject recruitment was more difficult than expected. Weight transmission success was high, but there was poor correlation between telemedicine system-measured oxygen saturation and a commercial monitor. The outpatient clinical telephone surveillance success rate for HC and ES was approximately 30%. After technical adjustments, parents of all ES (100%) were able to transmit questionnaire data. There were 9 emergency room visits for ES versus 11 unscheduled emergency room visits for HC. Sudden death occurred in 1 of 9 HC and 2 of 9 ES., Conclusions: Telemedicine monitoring for high-risk congenital heart disease patients is feasible but challenging, may reduce unscheduled visits, but may not impact the primary end point of preventing sudden death in this high-risk pediatric population.