Dale Irby, 63, said the whole stunt started out in 1974, when he wore the same outfit for picture day as he did the year before, the Dallas Morning News reported.
"I was so embarrassed when I got the school pictures back that second year and realized I had worn the very same thing as the first year," said Irby, an elementary school gym teacher.
Then, his wife dared him to wear the outfit -- a patterned polyester shirt and coffee-colored sweater -- again for a third year in a row.
"After five pictures," he said, "it was like: 'Why stop?'"
Irby wore the same outfit every year until he retired from Prestonwood Elementary this year.
"He took his job so seriously in teaching good sportsmanship -- both in athletics and in life," Prestonwood principal Pam Aitken said. "He taught a lot of kids to be fair and respectful of others. That's a great legacy to leave."