The accident took place on Jaffa street in the capital, just outside The Jerusalem Post offices.
"When we reached the scene the victim was laying unconscious near the motorcycle while suffering from a multi-system injury," said ZAKA volunteers Tzvi Yorovitz and Moshe Hemed.
The victim was apparently the son of a ZAKA volunteer.
He was evacuated to the Shaare Zedek Medical Center, where doctors pronounced his death.
Police on the scene are investigating the circumstances that led to the accident.