The inmate barricaded himself in a room in the Cowansville penitentiary, locking himself there with the worker who was in the area with him.
Correctional Service of Canada said nobody was injured in the incident at the medium-security prison, which holds 410 male inmates.
A negotiating team was called in soon after the incident began, around 10:45 a.m., and talks lasted more than nine hours before a resolution in the evening.
The man implicated in the hostage-taking will remain in the custody of the institution, said corrections spokesman Serge Abergel.
"We managed to reach an agreement with the prisoner. He agreed to release the hostage," Abergel said.
"I've heard that he released them in all security and that he agreed to turn himself in to correctional services personnel."
What did he ask for? Officials won't say, pending an investigation, but they suggested it might not have been very dramatic.
"These are sometimes things that can appear really trivial to must of us but, to them, might be important. Like for instance, concerns about access to the television room or about food."
Abergel would not confirm earlier reports that the hostage was female.
The accused hostage-taker could face new charges. The corrections service said more details of the case would be made available.
Once guards became aware of the incident Tuesday morning, the rest of the inmates were placed in lockdown in their cells to limit movement throughout the institution.
Provincial police were called in, and will lead an investigation into the case.