Ford is leading a delegation of about 70 Toronto business leaders on a three-day trip to meet Chicago's movers and shakers.
Ford met privately with Emanuel for 30 minutes Wednesday, after which the two gave prepared remarks to the media and re-signed the 1991 Sister City Agreement.
"For both Toronto and Chicago, this renewed commitment will help us both improve our strategic alliances, investment, trade, and learning opportunities," said Ford, who attended a breakfast with business leaders earlier in the day.
Emanuel said the two spoke about not only shared business opportunities, but what they could learn from each other as municipal leaders about topics ranging from city management to investment and infrastructure.
After signing the agreement, Ford headed to a luncheon speech from U.S. ambassador to Canada David Jacobson.
Later Wednesday there will be a tour of the Chicago waterfront.
Ford gives thumbs up to Chicago's waterfront
On Tuesday, at Millennium Park, Ford was effusive in his praise for what the city has done with its lake shore.
"I'd love to say Toronto, but people know Chicago more than Toronto, and why? It's because they have iconic things like this," Ford said.
The mayor says the city might be able to learn a lesson or two from Chicago when it comes to developing Toronto's Port Lands.
The Chicago trip is only the second foreign trip for Ford since becoming mayor in 2010.
Last year he travelled to Guadalajara, Mexico as part of the Toronto Pan American Games delegation.