Fisheries formed the basis of the Gulf’s economy for hundreds of years, and yet present-day statistical catch data remain inaccurate. When estimated, these catches often result in distinctly different baselines for historical catches, raising questions about how closely officially reported data resemble reality and the sustainability of certain management decisions. Here, we ‘reconstruct’ the contribution of missing sectors for all countries surrounding the Gulf (Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Arabia, and the UAE) from 1950 to 2010. Since the 1950s, Gulf countries have primarily reported their artisanal and industrial catches and have substantially misreported their discards, recreational, subsistence, and illegal fishing sectors. Our results suggest all countries in the Gulf under-report their catches, with the exception of the UAE, which over-report theirs. We show that regionally, officially reported catches potentially underestimate capture fisheries by a factor of two between 1950 and 2010, and that discards, mainly from shrimp trawlers, correspond to 18% of total landed catch. We discuss the discrepancy between reported and estimated catches, as well the policy implications for the region’s fisheries, food security, and marine ecosystems generally.