The objective of the study is to examine the efficiency of fisheries markets in Oman. Efficiency is measured in terms of two related criteria, namely; price and operational efficiency. Price efficiency is defined based on the economic theory, popularly referred to as Law Of One Price (LOOP). It is expected that if markets are perfectly competitive and, thereby, efficient, the price of a product will converge to one equilibrium price. Hence, if prices are different it could be due to imperfections of the market structure and/or due to operational inefficiency in relation to differential adoption of technology leading to differential wastes and costs in markets. The study initially tests for differences in prices in two comparable fish markets located in Muscat region, Seeb and Qurayat of three market agents, fishermen, retailers and truckers. Reasons for price differences are examined in terms of waste, costs and various natural factors. The data for the study have been obtained over a sample of 117 fishermen, 26 retailers and 44 truckers using separate questionnaires for each agent. Statistical tests were conducted to test for differences and relations. Fish prices among retailers and truckers were not found to be significantly different for most fish species. However, among fishermen of Seeb and Qurayat, the price of most fish species, particularly tuna, were significantly different. Hence, further analysis was conducted to examine imperfections of markets and operational inefficiencies of waste and cost. It was found that waste and cost were not significantly different between the two markets, indicating that operational inefficiencies did not contribute to price differences. A major reason explaining the price differences was the use of auctions, or otherwise, in the sale of fish. . The study concludes that fish markets are price and operationally efficient at retailer and trucker segments of the market supply chain. The markets are inefficient at the fishermen market segment of the supply chain where prices of most fish were statistically different, especially tuna as its price was more than twice the price of that in Seeb. This inefficiency is largely explained by use of competitive auctions in Qurayat market and not in the other. Hence promoting competitiveness in markets, particularly Seeb market, is recommended. Other recommendations relating to further improving operational efficiency (though both markets were equally efficient) through reduction of waste and cost might be achieved by providing infrastructure and facilities at levels of fishermen, truckers, and retailers. Providing a specialized landing facility such as harbor for Seeb's fishermen, and marketing facilities for on-shore retailers in Seeb, could reduce costs and waste, and enhance quality. Surplus supply is an issue common to all market agents, especially truckers. Therefore, it is recommended that truckers at Seeb market are afforded a specialized marketing facility, though not at fishermen landing and marketing site to avoid surplus supply. It is recommended that the public should be aware of different edible fish types by means of consuming behavior as 5.3% of truckers at Qurayat market claimed that demand is restricted and focused to particular types of fish.