TV shows such as BBC One's Life on Mars risk sparking homophobic bullying, according to a teachers' union.
More than seven million tuned in to see the finale
In Tuesday's final episode the character DCI Gene Hunt used a series of insults including "fairy boy".
Chris Keates of the NASUWT believes such language is "worrying" as children may not be taught that using this kind of abuse is wrong.
A BBC spokeswoman said the character is "extreme" and "tongue-in-cheek".
"Life On Mars is a post-watershed production, aimed at an adult audience. However, as with many dramatisations, we do not condone the actions of many of our fictional characters," she added.
Ms Keates, however, thinks if the bullying and name calling gets out of hand there could be dire consequences.
"Our evidence is showing that one of the factors which causes young people to consider suicide is the fact that in schools they are subject to homophobic bullying," she said.
More than seven million people tuned in to see the finale of the time-travelling detective series on Tuesday.
The BBC has announced a sequel to the show, in which DCI Hunt, played by Philip Glenister, moves from Manchester in the 1970s to London in the 1980s.