Four-year-old Aiden Clisham was let off on the wrong side of the Don Valley Parkway on his first day of school.
A Good Samaritan spotted the lost boy and called his school to notify them of what had happened.
The boy's father is concerned by the mishap and said more care should be taken to avert future problems.
Approximately 49,000 children are bused every day to Toronto's public and catholic schools.
The TDSB said it is looking at its busing procedures, and has a "zero tolerance approach to incidents like this."
The CBC's Michelle Cheung reports.