Weekdays feature mostly local talk hosts by day, with some syndicated shows in afternoons and nights, including Dave Ramsey, Lars Larson, Dana Loesch and Red Eye Radio.

KTSA was first licensed, with the call sign WCAR, on May 9, 1922, to John C. Rodriguez's Alamo Radio Electric Company at 608 West Evergreen Street.

WCAR was initially assigned to the sole available "entertainment wavelength" of the time, 360 meters (833 kHz), which required it to establish a time-sharing agreement with the other local stations.

[7] The call sign changed from WCAR to KTSA in early 1927,[8] reflecting the slogan "Kum To San Antonio",[1] and later that year the station was assigned to 1130 kHz.

[9] On November 11, 1928, with the implementation of the Federal Radio Commission's (FRC) General Order 40, KTSA was assigned to 1290 kHz on a time-sharing basis with KFUL in Galveston.

[11] KTSA carried the network's schedule of dramas, comedies, news, sports, soap operas, game shows and big band broadcasts during the Golden Age of Radio.

[13] The ad was aimed at advertisers who might otherwise want to buy time on NBC Red Network affiliate 1200 WOAI, which remains KTSA's rival to this day.

After KAKI-AM-FM letterhead and promotional materials were printed, management learned that the call letters could be pronounced as slang in Spanish for baby feces.

KTSA remained one of San Antonio's most listened-to stations until contemporary music listening switched to FM radio.

[16] In the 1980s, the Top 40 format moved over to KTFM, while KTSA switched to a full service adult contemporary sound, with some talk programming at night.

[18] KTSA staff inducted into the Texas Radio Hall of Fame include Ricci Ware, Brad Messer, Don Keyes, and Barry Kaye.