Police say four such incidents occurred between Jan. 22 and March 6, in the area bounded by Hwy. 401, St. Clair Avenue, Keele Street and Scarlett Road.
The students who were approached were 11 to 15 years of age. They reported the incidents to their parents and schools after they happened.
Det.-Sgt. Colin Greenaway told CBC News that schools in this area have been notified about these incidents. Police want to know more about the individual and want the public to know about the incidents.
"To date, he has not committed any criminal offences, but we are very concerned about why a person who is unknown to these four different children, in four different school locations, is asking the kids to come to [his] car," he said.
Greenaway said police "have a full-court press on right now," which includes a police presence in the area before and after school.
Police say the man in the car is somewhere between 20 and 40 years of age. Greenaway said he has brown skin, a slight beard and long, unkempt hair that may be in either dreadlocks or cornrows.
Greenaway said the man has been driving a mid-sized, white or cream-coloured vehicle.
Anyone with information is asked to contact police at 416-808-1200. Information can also be passed on anonymously through Crime Stoppers at 416-222-8477.