Murray cod (Maccullochella peelii) is an icon of the Murray-Darling River System (MDRS). There was a significant decline in the abundance of Murray cod throughout the late 1800s and 1900s, and it is now listed as threatened by the Commonwealth. Whilst, Murray cod stocks have improved throughout parts the MDRS, many aspects of its biology remains poorly understood. The aim of this project is to observe and describe the breeding behaviour of Murray cod in the wild using underwater video techniques. Murray cod were monitored over two breeding seasons (2011 and 2012) in Glen Lyon Dam and the Dumaresq River in the Border Rivers region of NSW and Qld. Aggregation and site selection commenced each year in Glen Lyon Dam in mid-August, with spawning taking place in late August - early September. Nest sites and eggs were also observed in the river over this same period. Murray cod males were observed selecting nesting sites, pairing, spawning and caring for eggs and larvae. From beginning to end the process took upwards of 20+ days. Nest sites were located on hard substrate and mainly underneath rocks in the dam, whilst in the river they were on cobbles in caves along undercut riverbanks. A second round of spawning in late September – early October was observed in the dam but not in the river. Underwater video has provided a valuable insight into the breeding behaviour of Murray cod. The results have already started to feed back into the wider management of the species.