The network's hosts include Kate Hawkesby, Mike Hosking, Kerre Woodham, Simon Barnett, James Daniels, Heather du Plessis-Allan, Marcus Lush, Andrew Dickens, Jack Tame and Francesca Rudkin.

[2][3] 1ZB originally operated from Broadcasting House, a purpose-built modernist theatre and studio building on Durham Street, from 1941 until its demolition in 1990.

[4][5] In the mid 1980s, 1ZB Auckland lost a number of its key on-air personalities to privately owned Radio i, including Merv Smith who had hosted 1ZB's breakfast programme for over twenty years.

Today most Newstalk ZB stations run complete networked programming, however Wellington and Christchurch still have a local show in the mornings between 9 am and 12 pm.

[2][3] Newstalk ZB's Auckland audience dropped dramatically in 2002 as music radio stations became more popular, raising questions about the future viability of the network.

[7] Paul Holmes caused controversy in September 2003, after he referred to United Nations Secretary General Kofi Annan as a "cheeky darkie".

[8] The Radio Network took disciplinary action against him, put their staff through a training seminar on racism run by race relations commissioner Joris de Bres, and a $10,000 donation was made to Save the Children.

On the same breakfast show Holmes asked whether the female journalists were making journalism "ignorant and bitchy", particularly at certain times of the month.

[12] The phrase featured on a commemorative tea towel,[13] and fellow broadcaster John Hawkesby remembered Holmes as a "cheeky little whitey" at his funeral in 2013.

[7] The same survey in 2014 showed Newstalk ZB lost 0.3% market share but gained 7,600 listeners during a time when other NZME radio stations were in decline.

[20] Host Rachel Smalley apologised in April 2014 after describing New Zealand women over 72 kilograms as "heifers" and a "bunch of lardos" during an ad break when she believed her microphone was off.

[25] Blogger Cameron Slater was a regular commentator on the drive programme for several years, and has been both critical and supportive of the station's positions in the past.

[26][27][28] In 2013, the Broadcasting Standards Authority rejected complaints against Slater over his suggestions that openly gay Labour MP Grant Robertson "enjoys being stabbed from behind" – and Newstalk ZB defended what they argued was "robust, irreverent, edgy" debate.

Regular callers include an urban Māori man, a state housing beneficiary, a security guard, a Timaru pensioner, a West Coast grandmother, a dairy farmer, a Dutch butcher and several taxi drivers.

Its most notable exclusive story was breaking the news about shoplifting allegations against former Green Party MP Golriz Ghahraman in early 2024.

[42][43] It extensively covers crime and court proceedings, but was criticised for publishing a wire story about the verdict against lawyer Davina Murray in 2013.

These updates for Auckland, Hamilton, Tauranga, Hawkes Bay, Wellington & Christchurch air every 15 minutes during peak breakfast and drive time slots, and hourly throughout the day and weekend on Newstalk ZB.

[54] Over several years, Newstalk ZB has given funding and support to Auckland Philharmonia Orchestra, visiting international productions and local theatre companies.

[60] In August 2024, The New Zealand Herald reported that Newstalk ZB's breakfast show's cumulative audience had increased from under 400,000 in early 2020 to 445,300 in 2024.

Newstalk ZB had 277,900 listeners in Auckland, doubling public competitor Radio New Zealand's Morning Report's in that city.

[61] The Broadcasting Standards Authority upheld a complaint in December 2014 about an editorial on the Israeli shelling of UNRWA Gaza shelters during the Israel-Gaza conflict.

Newstalk ZB argued the number of fatalities was irrelevant to the broader point, but the authority said the right to express opinions in editorials did not justify factually inaccurate and misleading statements.

The BSA found the programme breached the standards of good taste and decency, and discrimination and denigration, and ordered Newstalk ZB to issue a on-air statement and to pay $3,000 in costs.

The BSA found the programme breached the standards of accuracy, and discrimination and denigration, and ordered Newstalk ZB to issue a on-air statement and to pay $1,500 in costs.