Garcetti cited the Department of Water and Power, the Fire Department and the city's disparate information technology units as being high on his list for review, starting with potential changes at the top.
He also named the Library Department but added that problems there might be more a function of budget cuts than ineffective operations.
His comments came during a talk with the Los Angeles Times editorial board and in response to a question about which departments he viewed as needing a "change agent" to lead them forward.
"The DWP, certainly, is one that I think you need to have leadership from the commission, from the general manager, from whoever chairs the committee in the council," Garcetti said. "I think fire is another one."
Information technology is another area of concern, he said. Smaller departments are served by the Information Technology Agency while big departments have their own computer systems. Often the computer programs don't communicate well, he said.
"We have a really messed-up system,'' he said.
Garcetti said he will push for a chief technology officer tasked with coordinating and updating computer systems so they are more effective and user friendly for employees and the public.
During the campaign, Garcetti repeatedly said he would ask the city's general managers, roughly 30 in total, to reapply for their jobs. On Friday, he said it would take a "minimum" of two months to complete his review of top agency executives after he takes office.
Evaluating the City Hall's top management team and making changes where needed makes sense for a new administration, he said.
"I've just never understood why no mayor has ever taken advantage of that,'' he said. "You know, a president comes in, or a chief executive, and gets rid of everybody besides maybe one or two people."
Managers who are performing well shouldn't worry, Garcetti said. But he will be demanding measurable goals from department leaders so he can judge their performance going forward, he said.
"I don't know right now how to judge our general managers, except a couple, because we never have them say what they are going to be accomplishing,'' he said.
Ron Nichols, the DWP's general manager, said he looks forward to "working closely with Mayor-elect Garcetti" as the utility works to "eliminate our use of coal, increase our use of renewable energy and reduce our reliance on expensive imported water." Fire Chief Brian Cummings were not available for comment.