The intertwined issues of the delimitation of maritime boundaries and the division of the resources, particularly petroleum resources, of the Timor Sea have served as a persistent irritant in bilateral relations between Australia and East Timor since the latter’s independence in 2002. In 2003 an International Unitization Agreement for the Greater Sunrise complex of fields was signed. This was followed by the conclusion in 2006 of the Treaty on Certain Maritime Arrangements in the Timor Sea. The subsequent entry into force of these agreements, in February 2007, appears to resolve this contentious dispute, at least for the foreseeable future. This article explores the background to the dispute and positions of the parties, traces the progress of negotiations towards its interim resolution and then assesses the agreements themselves. It is concluded that while the agreements are, on balance, somewhat more favourable to Australia than to East Timor, they can still be viewed as beneficial to both parties.