The application of FRP composite is quite well demonstrated in strengthening on RC structures but on strengthening of steel structures is still being investigated by many researchers. The aggressive marine environment can cause corrosion to the offshore pipelines which would affect the structural performance such as pitting corrosion which could be considered as the most destructive corrosion was simulated in this research. This study had attempted to carry out experimental investigation of effectiveness of FRP composite repair system on offshore pipelines subjected to pitting corrosion under axial compressive load. 3 groups of specimens have been categorized such as intact, corroded and repaired. Results such as compressive peak load, failure modes and load�displacement behavior were concerned in this study. The pitting corrosion has been investigated and proved that it has significant effect on the ultimate strength of pipelines. Number of CFRP layer such as 3 layers has been investigated which the results showed the FRP composite repair system capable of strengthening of corroded offshore pipelines. However, more detailed studies are required to be conducted in the future such as consideration of internal pressure in order to expand the understanding of this composite repair system. © 2023, The Author(s).