We present the progress report of the IOTC bigeye thresher shark post-release mortality study project (IOTC BTH PRM Project). The goal of the study is to evaluate the efficiency of the IOTC Conservation and Management Measure on non-retention of thresher sharks of the genus Alopias (Resolution 12/09). The summary of the collective efforts since the 13th and 14th IOTC WPEB are presented here, including development of formal documents, operating standard manuals, training, PSATs distribution, and field operations. Further steps for the project implementation are also described.