Most commercial fisheries have experienced dramatic declines in fish stocks sourced by overcapacity, and thus, there has been a decline in the economic benefits of fishermen, industries, and regions that rely on fisheries for their support in Samsun. Therefore, the study evaluated productive efficiency measures for large scale modern commercial fishermen in Samsun Province, Turkey. Data envelopment analysis (DEA) was used to calculate productive efficiency measures. 55 trawlers and 65 fishermen who prefer to use trawlers together with seine fishing were interviewed in the 2007-2008 production periods. Research results showed that the mean economic efficiency of trawlers and the fishermen preferring to use trawlers together with seine fishing were 0.535 and 0.667, respectively. In Samsun, the primary source of economic inefficiency for trawlers was allocative inefficiency, while that of mixed fishermen was technical inefficiency. Decomposition of the technical efficiency showed that pure technical efficiency was the primary cause of the technical inefficiency for both trawlers and mixed fishermen. Most fishermen in both fishing types exhibited increasing return to scale. Research fmdings also revealed that basic source of inefficiency was overcapacity problems sourced by market failures and restrictions on season length in the research area. Policy measures aimed at developing training and extension programs, helping fishermen improve their technical information, eliminating inefficiency sourced by overcapacity, sustainable use of the fish stocks, and encouraging fishermen to obtain higher added value from fish and other sea products via processing, packing and storing fish instead of increasing fish production are recommended to increase productive efficiency in the research area.