The site in question is at the intersection of Lincoln Avenue and Webster Street and involves the former Lincoln Park hospital building.
Protesters, led by three former 43rd Ward aldermen, gathered Sunday to voice their disapproval over part of the developer's plan.
The owners of the site want to turn the hospital into condominiums and retail space, but their plan also calls for a grocery store across the street, and protesters say that would create too much congestion.
"This intersection over here is already jammed at rush hour, and the back-ups on Webster caused by trucks will cause unacceptable and unwarranted traffic jams," said William Singer, a former alderman who opposes the land.
"We are excited to bring this project to the neighborhood to reuse the existing building, creation of jobs that will be here," said Sandz Development's David Goldman.
The development company also says it is refining plans to suit as many neighbors as possible.