President of basketball operations Donnie Nelson said the ban was lifted after the eight-year veteran met with Nelson and Mavericks coach Rick Carlisle on Tuesday.
After Monday night's preseason win over Houston, Carlisle told reporters West was suspended without offering any details.
West has bipolar disorder. He was suspended for the first 10 games of the 2010-11 season after pleading guilty to weapons charges in Maryland. Authorities say he was carrying three loaded guns and a knife when he was stopped for speeding on a three-wheel motorcycle in 2009.
West was a valuable player off the Dallas bench last season and is expected to fill a similar role in 2012-13.