Chicago police said there were 28 homicides last month, which is six more than 2010.
Last year, the city had the fewest murders since 1965.
Still, overall violent crime fell 10.2 percent and property crime was down 10.7 percent.
At police headquarters Sunday, Superintendent Jody Weis said he was pleased by the decrease in crime, but said the only acceptable number for violent crimes and homicides is zero.
"We cannot ignore the destructive nature of gangs, guns and how their presence can escalate a volatile situation to a tragic one," Weis said. "The majority of homicides in January almost 72 percent were committed with a gun."
"In the month of January alone, more than 560 guns were taken off the street with 30 being assault weapons. Almost one a day," Weis said.
Weis said January was the 25th consecutive month that the city had a drop in overall crime.