South Yorkshire Fire and Rescue Service received the comments after it posted a rainbow flag on Facebook last year to show support for LGBT people.
In has released a “defiant” video showing firefighters and staff members reading comments posted by “trolls “.
In it, the service says:” Fires don’t discriminate, neither do we. “
One comment read out by a member of staff said: “Let’s see pictures of our firefighters doing their job and keep political correctness out of it. “
Chief fire officer Alex Johnson said: “We fully expect the video will have a mixed reaction but some of the comments we received last year were awful and totally unacceptable.
“We’ve produced it for two reasons – firstly we wanted to support the month and let our staff, and communities, know that we are proud to employ and serve them, regardless of those comments.
“And secondly we wanted to demonstrate that we are a genuinely inclusive organization that values the contribution of all our staff, whatever their LGBT status. “
In June last year, organization added the rainbow flag, A symbol seen at pride events around the world , to its Facebook display picture.
South Yorkshire Fire and Rescue Service said some of the comments received were too offensive to be used in the video.
One comment said: “I can only hope someone hacked your Facebook account and put this on.”
Crew manager Rebecca Savin, South Yorkshire Fire Brigades Union’s LGBT rep, said: “It’s great that as an employer, South Yorkshire Fire and Rescue Service wants to challenge these comments and stand up for its staff and the people it serves. “
Ms Savin said she hoped their stance would help staff to bring their “authentic selves” to work while also encouraging more people from the LGBT community to consider careers in the fire service.