Tom Porton is used to drama: Since arriving at James Monroe High School as an English teacher 45 years ago, he has taught and staged plays. Outside, in the Bronx River neighborhood where the school is, there was plenty of drama in the 1980s, when AIDS and crack ravaged the area. His response then was to establish a group of peer educators who worked with Montefiore Medical Center to teach teenagers about H.I.V. prevention. His efforts earned him awards, including recognition from the City Council and the John F. Kennedy Center for the Performing Arts, and led to his induction into the National Teachers Hall of Fame.

Now he is at the center of drama: Last month he clashed with Brendan Lyons, the school’s principal, who disapproved of his distributing H.I.V./AIDS education fliers that listed nonsexual ways of “Making Love Without Doin’ It” (including advice to “read a book together”). This month, he said the principal eliminated his early-morning civic leadership class, which engaged students in activities such as feeding the homeless, saying it was not part of the Common Core curriculum. Mr. Porton was already skeptical of that curriculum, saying it shortchanged students by focusing on chapters of novels and nonfiction essays rather than entire works of literature.

So, next month Mr. Porton — a 67-year-old educator whom students praised as a lifesaver and life-changer — is walking away from teaching. He handed in his retirement papers on Friday.

“My career has always been based on the emotional and social well-being of the child,” he said, inside an office whose walls were decorated with awards, proclamations and photos of him alongside several school chancellors; Michael R. Bloomberg, the mayor at the time; and the rapper DMC. “Now, I don’t know where teaching is headed. I just know I can’t anymore. I find it torture. I’d rather separate myself from the classroom doing something that is distasteful and try to spend my days doing things that are important.”