Joel Schaeffer, Reseda High's football coach for the last 23 years, announced his resignation Thursday.
"All good things come to an end," said Schaeffer, who guided Reseda to a City 2-A championship in 1986 and a 3-A championship in 1995.
Schaeffer, 58, had a record of 157-95-5. His teams made the playoffs 19 times and won six league championships.
He was known for teaching fundamentals and discipline.
"This is probably the toughest decision I've made in my life," Schaeffer said. "I haven't been off the football field since I was 14 years old."
Schaeffer plans to continue teaching at Reseda, where he coordinates the school's police magnet program.