Introduction: Telemedicine use in the Critical Care setting has been described and some delivery models have demonstrated improved outcomes. We have previously reported our initial experience with Telemedicine in the International Pediatric Cardiac Critical Care (PCCC) setting. Nonetheless, optimal method of delivery has not been established. Methods: Retrospective review of clinical records and a Telemedicine clinical database of patients admitted to the CICU from FCV, who were tele-assisted by CHP during the initial 10 months of our program, compared with patients admitted during a previous period. Information collected included demographic data, cardiac diagnosis and associated factors, RACHS-1 classification and perioperative events. Primary outcome was composed by CICU and Hospital Mortality, with CICU and Hospital length of stay (LOS) as secondary outcomes. Results: 553 patients were included in the study, and 71 (12.4%) were tele-consulted with a total of 156 encounters, including 19 for patients on ECMO. 321 recommendations were given and 42 real-time interventions were documented. RACHS-1 distribution was similar between study periods (p=0.427). Teleconsulted patients were significantly younger (44 vs vs 24 months p=0.03) and had higher surgical complexity than no teleconsulted patients as compared with RACHS-1 distribution (p=0.01). There was a higher proportion of ECMO patients in Telemedicine study period (4.9 vs 1.6% p=0.030). RACHS-1 adjusted CICU and hospital survival was similar between study periods. CICU and Hospital LOS were significantly shorter in the Telemedicine period (10 vs. 17 days, p=0.02; and 22 vs. 28 days, p<0.001). In primary cardiac surgical cases, CICU LOS before surgery was significantly shorter (3 vs. 6 days p<0.001). Variables associated with CICU & Hospital mortality were RACHS-1 category, younger and lower weight patients, use of circulatory arrest, prolonged By-Pass and CC times, LCOS, sepsis, NEC and ECMO. In addition, those associated with increased LOS were ventricular failure, diaphragmatic or vocal cord paresis, AKI, and postoperative hemorrage. Conclusions: An International Telemedicine service in PCCC was associated with lower CICU and Hospital LOS. Prospective telemedicine interventions aimed to decrease mortality and LOS should focus on patients with higher RACHS-1 category, neonates and lower weight, those with prolonged operative time and selective perioperative complications.