We investigated 26 B‐cell post‐transplant lymphoproliferative disorders (B‐PTLD) and 15 human immunodeficiency virus‐related aggressive B‐cell lymphomas (HIV‐BCL) from England that were associated with Epstein–Barr virus (EBV) for the polymorphic sequences of the EBV‐encoded nuclear antigen 3C (EBNA3C) gene to distinguish the two different EBV strains. Type‐A‐EBV was identified in 92% of B‐PTLDS and in 53% of HIV‐BCL (P = 0.003). Among HIV‐BCL, patients associated with type‐B‐EBV had been HIV positive for significantly longer when compared to those associated with type‐A (P = 0.037) although there were no correlations with ethnicity, CD4 cell counts or plasma HIV viral load.