In this study, Stock Synthesis (SS) was applied to conduct the stock assessment for blue marlin in the Indian Ocean. The analyses were performed by incorporating historical catch, standardized CPUE series and length-frequency data. The results of most scenarios indicated that the current stock status of blue marlin in the Indian Ocean was not overfished and not overfishing, but it may be subject to overfishing and overfished when fixed natural mortality and two-area assumptions were used. It should be noted that most of the life-history parameters used in this study were based on the values of blue marlin in the Pacific Ocean and this may lead to uncertainties in the evaluation of the stock status of blue marlin in the Indian Ocean