Three NUP98 chimaeras have previously been reported in T cell acute lymphoblastic leukaemia (T-ALL): NUP98/ADD3, NUP98/CCDC28A, and NUP98/RAP1GDS1. We report a T-ALL with t(11;18)(p15;q12) resulting in a novel NUP98 fusion. Fluorescent in situ hybridisation showed NUP98 and SET binding protein 1(SETBP1) fusion signals; other analyses showed that exon 12 of NUP98 was fused in-frame with exon 5 of SETBP1. Nested polymerase chain reaction did not amplify the reciprocal SETBP1/NUP98, suggesting that NUP98/SETBP1 transcript is pathogenetically important. SETBP1 has previously not been implicated in leukaemias; however, it encodes a protein that specifically interacts with SET, fused to NUP214 in a case of acute undifferentiated leukaemia.