As the only television station that was built from the ground up by the Westinghouse Electric Corporation, WBZ-TV began operations 10 a.m. at June 9, 1948, with test patterns.

Due to the uncertainty surrounding the exact day the station would launch, all of the messages were prerecorded and one of the speakers (Liebman) had died before the program aired.

The station originally operated from inside the Hotel Bradford alongside its radio sister; its current home was not completed at the time, although master control and its self-supporting tower over the building were in use at sign-on.

The swap was made in February 1956, and Westinghouse immediately complained to the Federal Communications Commission (FCC) and the U.S. Department of Justice about NBC's extortion.

On October 12, 1957, WBZ-TV broadcast a half-hour special program on Sputnik 1, featuring a motion picture of the final stage of its rocket crossing the pre-dawn sky of Baltimore, shot by sister station WJZ-TV.

[10] The station was the first in the Boston market to employ a female reporter (Betty Adams), the first to employ a Black full-time reporter (Terry Carter), the first to have an all-female news team (Shelby Scott and Gail Harris), the first to have a Black full-time nightly news anchor (Liz Walker), and the first to air a minority affairs program.

[11] Westinghouse felt betrayed by ABC's decision, and as a safeguard began shopping for affiliation deals for the entire Group W television unit.

After the 2000 acquisition of CBS by its former subsidiary, Viacom, which effectively made the station locally owned because Viacom's parent National Amusements is based in the suburbs of Boston, WBZ-TV's operations were merged with that of Boston's UPN affiliate, WSBK-TV; concurrently, WBZ-TV also took over the operations of WLWC, the UPN affiliate in nearby Providence, which had been run out of WSBK-TV.

While CBS shareholders retained a 72% ownership stake in the combined company, Entercom was the surviving entity, separating WBZ (AM) and its sister radio stations from WBZ-TV.

In January 1983, when People Are Talking expanded to one hour, WBZ-TV dropped the NBC soap opera Another World, which moved first to WQTV, then to Worcester-based WHLL-TV (now WUTF-TV), and finally, in the early 1990s, Lawrence-licensed WMFP.

In 2005, WBZ aired a special documentary film directed by Michael Bavaro titled Rex Trailer's Boomtown featuring old clips and interviews with childhood fans such as Jay Leno, Steven Wright, Tom Bergeron and Jimmy Tingle.

In September 1990, due to a decline in the franchise's popularity and tabloid TV magazines heralding bigger ratings and revenue, Group W canceled Evening/PM, with the last WBZ broadcast airing on December 17 of that year.

During the station's 6 p.m. newscast, graphic slides featuring the Lottery and The Numbers Game logos would appear with the nightly results from the Boston and Tri-State (Maine, New Hampshire and Vermont) regions.

Eleven years after leaving its original station, Lottery Live returned to WBZ on May 20, 1998, with longtime host Dawn Hayes (from the WNEV/WHDH era) still at the helm.

From 2003 through 2016, WBZ produced coverage of the Boston Pops Orchestra's annual Fourth of July concert at the Hatch Memorial Shell.

ET hour of the show was broadcast nationally by CBS – featuring the Pops' signature performances of the 1812 Overture and "Stars and Stripes Forever", as well as the fireworks over the Charles River.

On July 21, 1979, a new format premiered in this time slot: Live on 4, a more informal program mixing elements of a daytime talk show with those of a traditional newscast, went on to become a trendsetter in the Boston market in the 1980s.

First, it premiered the two-hour live talk/magazine show Look in the fall of 1982 (renamed New England Afternoon in its second and final year), it failed in the Nielsen ratings and was canceled in 1984.

Although this competitor to Live on 4 drew high ratings, the format ended after only a year, due to the departure of its creator, anchor Dave Wright.

In the early 1980s, WBZ-TV lost its longtime spot as Boston's highest-rated news station to WCVB, but even then placed a strong second for more than a decade.

Williams remained at WBZ until his retirement in June 2015, Walker gave up anchoring duties in 2005 and hosted a Sunday morning talk show for several years before leaving the station in October 2008.

When ACA moved to WCVB's late night schedule in the fall of 1993 (later moving to WHDH's daytime lineup in 1994), WBZ switched their late afternoon newscast to 5:30 pm, and began airing the freshman syndicated series American Journal (with WBZ alumnus Nancy Glass as anchor) at its 5 p.m. lead-in.

The move was done in the hopes of re-emphasizing WBZ-TV's local identity and trading on the call letters' then eight-decade history in Boston—a strategy that worked well when Piette was general manager at Minneapolis–Saint Paul sister station WCCO-TV.

In addition, Ed Carroll's contract was not renewed and in October 2005 the station hired Ken Barlow from KARE in Minneapolis, Minnesota, to replace him as chief meteorologist.

In January 2007, the station launched Project Mass,[37] a commitment to cover the community's top concerns in government, transit, healthcare, education, finance and the environment.

As a result of the budget cuts, roughly 30 staffers were released from WBZ-TV and WSBK-TV, including longtime sports director Bob Lobel, entertainment reporter Joyce Kulhawik, and WSBK anchor Scott Wahle.

On June 6, 2008, weekend anchor/reporter Kate Merrill was appointed as 9 p.m. anchor on WSBK, along with general assignment reporting duties for the weekday 5 p.m. and 6 p.m. newscasts.

Even with the budget cuts at CBS, WBZ-TV's 11 p.m. newscast was number one in its time slot in the 2007–08 season (it has since slipped back to second place).

[42][43] On December 12, 2011, WBZ debuted a new news set, replacing one that had been used for nearly a decade, it features LED lighting, a dedicated weather area, and 16 high definition monitors.

As part of the SAFER Act, WBZ temporarily kept its analog channel on the air to broadcast information regarding the transition to digital television.