Objective: To evaluate Immunophenotyping patterns in Mixed-Phenotype Acute Leukemias (MPAL). Study Design: Descriptive study. Place and Duration of Study: This study was carried out in the department of Hematology, Armed Forces Institute of Pathology Rawalpindi, from 1st Jan 2013 to 31st Jan 2017. Material and Methods: After taking informed consent from the patients fulfilling the inclusion criteria, detailed history was taken and blood samples were drawn for blood complete picture. The patients suspected to have acute leukemia were subjected to bone marrow examination (aspiration and trephine biopsy) for further cytochemical staining (SBB) and Immunophenotyping. Results: Total 680 new cases of acute leukemias on initial workup of either gender age were included. Patients of other haematological disorders were excluded from the study. Among 680 new cases of acute leukaemia, 23(3.4%) cases were of MPAL immunophenotyping using scoring system proposed by EGIL (European Group for the Immunological Characterization of Leukemias) classification. Among MPAL, 19(83%) cases were Biphenotypic [13(57%) cases of My/B-ALL, 5(22%) cases of My/T-ALL, and 1(4%) case of T/B-ALL]. 4(17%) cases were Bilineage (My/B-ALL). Most of the cases were diagnosed at less than 10 years of age. Conclusion: My/B-ALL is the most common immunophenotype followed by My/T-ALL. Therefore immunophenotyping is indispensable for diagnosis and for therapy decisions of MPAL.