AbstractDue to its high compressive strain of at least 0.5%, which is higher than both the yield strain (0.35%) of high strength steel (HSS) and the compressive strain (0.23%) of normal strength concrete (NSC), Engineered Cementitious Composites (ECC) is a material with high potential to replace NSC in HSS composite beam construction. This study reports an experimental investigation on the flexural behaviour of HSS‐ECC composite beam fabricated by using HSS I‐section in conjunction with hybrid polyethylene‐steel fibers (PE‐ST) ECC slab. Shear connection between the HSS I‐section and the top PE‐ST ECC slab was constructed by using normal profiled steel sheeting and headed shear studs. A HSS‐ECC composite beam and a HSS‐NSC composite beam were cast and tested under four‐point bending. The test results revealed that a large area of HSS I‐section in HSS‐ECC composite beam yielded compared to only a small yielded area of which in the HSS‐NSC counterpart despite the fact that both composite beams have identical configuration and silimar mechanical properties. The HSS‐NSC beam underwent longitudinal shear failure while in contrast, the HSS‐ECC beam failed by flexure and exhibited great ductility.