The group also said members would hand out safety tips.
The announcement came after three children said they were approached by a man as they walked to school last Friday. The children were on their way to Chicago International Charter School at 110 East 61st Street when they said a man in a white van tried to lure them inside at approximately 7:15 a.m.
After the Friday incident, police said they reviewed a similar, separate incident. Another child said she was approached by a man in a car in the same area last week.
Chicago police say they have decided both cases were not bona fide.
Still, the Guardian Angels said they would be out and about from 6 a.m. to 9 a.m. Monday to look out for the safety of the children.