The workers are members of Kesk, a federation of public-sector unions, and include many members of the teachers' union Egitim Sen.
The arrests come in the aftermath of a suicide bomb attack on the US embassy in Ankara on February 1, carried out by a self-styled "leftist" terrorist group.
This move is a transparent attempt by the Turkish government to link legitimate, democratic trade unions with an act of terrorism.
Sadly mass arrests of trade unionists are not uncommon in Turkey.
It is a favourite tactic of intimidation periodically used by the Turkish state.
Last June 72 other members of Kesk were lifted in a similar fashion and will go on trial in April.
Last February nine of Kesk's women members were arrested after the union announced its programme of activities for International Women's Day.
LabourStart has launched an online campaign for the release of these workers, in partnership with the ITUC and two global union federations.
We are calling for online letters of protest to be sent to the Turkish prime minister, which can be done by visiting www.labourstart.org and clicking on our Act Now campaigns page.
The first 24 hours saw, on average, one message going off every 12 seconds.
We need to keep this up as one part of a strategy to free these workers.
We are asking anyone in the union movement, particularly public sector unions, to forward this on to their email lists and spread the word as widely as possible.
Edd Mustill
LabourStart
London N17