Police are investigating a collision in Point Cook that occurred on Thursday, 25 August.
It is understood a car and cyclist collided on Atlantis Drive at about 4.15 pm.
The 15-year-old male cyclist was taken to the Royal Melbourne Hospital.
An ambulance spokesperson told Wyndham TV that the boy was taken by ambulance in serious condition and had suffered upper body injuries.
The driver of the vehicle, a 30-year-old male, stopped at the scene.
Anyone who witnessed the incident has dashcam footage or information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppers.com.au