The epidemiology, safety, and efficacy of pediatric multiple tandem extracorporeal therapies are not well understood. We conducted a retrospective chart review of therapeutic apheresis (TA) from January 1, 2012 to October 31, 2015. We collected procedural/clinical demographics, American Society for Apheresis (ASFA) indication, complications, and mortality. One hundred eighty tandem TA procedures were performed in 53 patients. Median age was 9 years (range: 2 months to 21 years) with a median weight of 28 kg (range: 6–170.3 kg) with nine patients weighing < 10 kg. Forty-five percent of patients were in tandem with continuous veno-venous hemofiltration (CVVH), 21% cardiopulmonary bypass (CPB), 4% extracorporeal membrane oxygenation (ECMO), and 11% had multiple extracorporeal therapies (CVVH and ECMO). Common indications were solid organ transplant (50% cardiac, 13% renal) and sepsis-induced thrombocytopenia-associated multiple organ failure (26%). Equipment (4%) and patient (4%) complications occurred, with rare failure (1%) and no procedure-related mortality. Tandem procedures are used in critically ill pediatric patients with higher morbidity and mortality (21%) than typical TA patients. The high percentage of patients outside of category I or II (83%) underscores the emerging nature of tandem extracorporeal therapies and need for further investigation.