Kansas City, Houston, St. Louis, Memphis and Knoxville are among 14 cities no longer on the original schedule released in May, according to a revised itinerary posted Thursday on the Dixie Chick's Web site.
Other shows, including Nashville, Los Angeles, Denver and Phoenix, have been pushed back to later dates.
The North American leg of the tour kicked off July 21 in Detroit. Billboard magazine and other trade publications have reported lackluster sales in some markets, particularly in the South and Midwest.
Group spokeswoman Kathy Allmand said Monday that the total number of North American dates remains the same, with several Canadian cities added in place of the U.S. shows.
The trio released a statement last week attributing the changes to attempts to "accommodate demand" and said more dates might be added next year.
The group also said the adjustments will allow them to promote the documentary "Dixie Chicks: Shut up and Sing," for the Toronto International Film Festival in September.
"We hope that our fans who were looking forward to a stop that is no longer on the tour will be able to join us at a nearby arena this fall, and we are sorry for any confusion or inconvenience these changes have caused," the Dixie Chicks said.
Many country fans criticized the band after lead singer Natalie Maines told a London audience in 2003 on the eve of war in Iraq that the trio was "ashamed" President Bush was from their home state of Texas.
County radio stations dropped them from their playlists and have been slow to welcome them back, despite strong sales of their latest album, "Taking the Long Way."
The album, which has more of a rock edge than their previous releases, spent several weeks at the top of the country albums chart and has sold more than 1 million copies.