In 2005, the Sting defeated the 2004 NLL champion Calgary Roughnecks to win the franchise's first-ever West Division title. The Sting fell 19-13 to the East Division champion Toronto Rock in the league championships.
On October 16, 2007, the NLL announced that the 2008 season had been cancelled due to the failure of the league and the Professional Lacrosse Players' Association to reach a new collective bargaining agreement. However, the negotiations continued and, on October 25, the league announced that a new seven-year agreement had been reached, and that the season would be played. A new schedule was announced on November 2, 2007, but only included 12 of the expected 14 teams; the Sting and Boston Blazers had been removed. According to a news article posted on the Sting website,
When the NLL Board of Governors cancelled the season on Oct. 16, we ceased our Arizona Sting business operations. On Oct. 25, when the two sides came to an agreement on a new seven-year CBA, the league announced that there would be a season in 2008. The NLL then gave all clubs an option to be placed on voluntary inactive status, whereby the team’s players could be subject to a dispersal draft. Dispersed players may be loaned to other NLL clubs for the 2008 season and returned to their original clubs in 2009. At that time we reviewed our organization and the challenges we faced with fielding and operating a championship-caliber club both on and off the field in a reduced time frame. After our review we made a very difficult decision to declare inactive status for the 2008 season.