The vote came after complaints from administrators at Maine West High School that vaping, or breathing in vaporized liquid nicotine, is a growing distraction during school.
WATCH: What you need to know about 'Juuling'
Products like Juul, which is shaped like a USB flash drive, heat liquid nicotine into an inhalable vapor.
Juul is increasingly popular, a trend noticed by Mike Beauvais, a student resource officer assigned to Maine West High School.
"Lately, they've been doing it in the hallways, in the bathrooms, in class, just all over," said Beauvais.
Maine West administrators worked with Des Plaines police to push the city council to adopt an ordinance for students caught vaping or smoking e-cigarettes.
The vote Monday night expanded Des Plaines' municipal tobacco smoking ban for people under 18 to include vaporizers and e-cigarettes.
Underage students caught doing it won't necessarily face a fine; instead, they'll have the option to attend a class on the dangers of smoking and vaping.
"This gives us an opportunity to rather than financially punish the students, to put them in a diversion program," said Des Plaines police chief William Kushner.
The seven-person council passed the measure 6-1. The only alderman who voted against it did so because he felt the ordinance should apply to anyone under the age of 21 rather than 18.
Juul can be found at Wise Guys Vape shop, a block away from Maine West. A sign on the shop says no on under 18 is admitted.
Still, Beauvais says more and more minors are vaping.
"Most of the kids know it's wrong, but they don't really see a big problem with it. I just don't think they know what they're putting in the body," he said.
Many parents support Maine West's efforts to crack down on vaping.
"I don't think they should be allowed to Vape or smoke as far as school is concerned," parent Mary Aguirre said.
"I would talk to them about the consequences and health hazards to it," parent Donna Rivera said.
Students caught vaping who choose the diversion class rather than a fine must be accompanied by a parent or guardian when they attend the class.