The lack of coarse aggregate is a prominent factor contributing to the relatively low modulus of elasticity (ME) seen in engineered cementitious composites (ECCs). In contrast, the accumulation of graphene oxide (GO) into cementitious composites has resulted in enhancements in their deformation characteristics. However, the ME and Poisson's ratio (PR) of ECC are influenced by the curing period, among several other factors. The objective of the experimental investigation is to examine the impact of GO on the long-term ME and PR of ECC, including different volume fractions of Polyvinyl Alcohol (PVA) fibre. Moreover, the cylindrical specimens (300 mm � 150 mm) were subjected to testing for the parameters ME and PR at two years after exposure to water. Besides, the testing was completed in accordance with the guidelines outlined in ASTM C496. It has been observed that the ME was recorded 30.20 GPa at 0.05 of GO along with 1 of PVA fibre which is greater than control mixture while the PR was noted by 0.17 at 0.05 of GO along with 1 of PVA which is 15 lesser than control mixture after two years correspondingly. Based on the findings, the incorporation of GO and the extension of the curing period had a positive influence on the ME and PR of all specimens. © 2024 Elsevier B.V.