Iran is among the pioneers in the farming of rainbow trout that is mostly up to 1 kg with a production of 173,000 tonnes in 2018, principally used for domestic consumption. Farmers use labour-intensive hand feeding and counting eggs by hand. Imported trout eggs are preferred to domestic eggs as they have a lower a feed conversion rate than Iranian eggs. There is also an import subsidy on foreign trout eggs to enhance food production. Some farms cannot obtain them because of sanctions. This is a threat to food security. Despite the subsidy, the average cost for imported eggs is more than for domestic. Nevertheless, the economic efficiency of import-dependent trout supply chains versus independent supply chains needs to be clarified. Network data envelopment analysis is adopted to analyse trout supply chains in Mazandaran Province, the centre of Iranian trout farming, in 2018. It is found that the supply chains made almost maximum use of their inputs and are technically efficient. However, allocative efficiency was significantly different between the supply chains. As a result, the average economic efficiency of import- independent supply chains is higher than that of the dependent ones. The high economic efficiency of the independent supply chains is identified to stem from vertical integration and domestic egg propagation. Moreover, economic efficiency and food security could be enhanced along with domestic propagation by reducing feed costs, abolishing subsidies, and granting financial resources to the capital-intensive technologies rather than labour-intensive ones that could decrease the cost of labour.