The 26-year-old, who bagged 25 goals for the Gills on loan from Norwich in 2010/11, returned to Priestfield at the end of January on an agreement until the end of the season in a bid to regain his scoring touch.
But City, short of firepower up front, have now taken the option to activate a recall clause after 28 days of McDonald's stay in Kent having watched him bag four goals in seven appearances for the League Two promotion chasers.
Gillingham boss Martin Allen told the club's official website: "We have just been contacted by Coventry and they have recalled Cody McDonald.
"I am sure that each and every one of us are very grateful for the way that Cody has conducted himself on and off the pitch.
"Off the field he has been a model professional. Hard-working, dedicated and committed to our club.
"On the field he has been honest, hungry and deadly."