More than 250 journalists at The Herald, Sunday Herald and Evening Times newspapers have begun strike action.
Herald newspaper group staff walked out over cuts
The dispute began after some staff at the Evening Times were warned about compulsory redundancies.
Newsquest, which bought the group in 2003, said it regretted the strike action and that it planned to publish its titles as normal.
It is the first strike at a major Scottish newspaper group since the Aberdeen Journals dispute in 1989-90.
The staff walked out at 1500 BST, accompanied by a piper.
The strike will affect production of Saturday's Herald and the Sunday Herald which will have only a skeleton staff.
A further strike is planned for next week.
Newsquest has made £3m of cuts, resulting in 100 job losses at the three titles.
The National Union of Journalists (NUJ) has expressed wider concern about how the papers are being run.
The union said journalists had overwhelmingly backed strike action.
However, The Herald and Times' managing director, Tim Blott, said: "We deeply regret the decision of the NUJ to continue its proposed strike even though the number of people facing compulsory redundancy has now dropped to one out of a total of 300 editorial staff."
"We are successfully running a 21st Century multi-media business with all its competitive challenges. We will continue to publish our newspapers as normal."