We report a 15-year-old cardiac transplant recipient who developed a monomorphic posttransplant lymphoproliferative disorder (PTLPD) which demonstrated morphological and immunohistochemical features of anaplastic large cell lymphoma including CD30 and anaplastic lymphoma kinase (ALK) immunopositivity but lacking the commonly associated t(2;5) translocation. The neoplastic cells were Epstein-Barr Virus (EBV)-negative. T-cell PTLPD is an uncommon but recognized late complication in solid organ transplant recipients. This is the first reported case, to our knowledge, of PTLPD occurring in childhood with an ALK+, CD30+ anaplastic large cell lymphoma phenotype.