Triple Hit Lymphoma (THL) is an extremely rare and aggressive form of Non-Hodgkin's lymphoma with morphologic, phenotypic and genetic features of both diffuse large B cell lymphoma (DLBCL) and Burkitt's lymphoma (BL). Its characteristic cytogenetic abnormalities involve chromosomal rearrangements of c-MYC, BCL-2, and BCL-6 genes. It has been recognised, in the 2016-revised WHO classification of lymphoid neoplasms, as "Highgrade B-cell lymphoma, with MYC and BCL2 and/or BCL6 rearrangements". We describe a case of a 68 years old male with two years history of stable low-grade follicular lymphoma suddenly transforming into acute leukaemia caused by THL. During the aggressively progressive phase, he developed Non-ST Elevation MI (NSTEMI), diagnosed by raised troponin and new anterolateral ST depressions on his ECG. His MI was attributed to leukostasis, anaemia and coagulopathy. THL carries poorer prognosis than either DLBCL or BL alone; thus it should be recognised as haematological emergency.