The plea was entered at a brief court hearing Thursday by defense attorney Christopher Lyons. The 28-year-old Stallworth did not appear in court. A trial date has not been set.
Stallworth faces up to 15 years if convicted. Police say Stallworth was driving drunk after a night on the town when he struck and killed 59-year-old Mario Reyes on a Miami Beach causeway.
Stallworth is free on $200,000 bail and is required to abstain from alcohol, not drive and observe a curfew.