At the MexicoOlympics, Greene felt pain in his hamstring late in the race and was third in the 100 m. He was the fastest man in the trials and semifinals but before the final race he was injured but started anyway with a bandaged leg. Despite the injury, he also led off the American 4x100 m relay team that won the gold medal and set a new world record of 38.19.
Following his athletic career, Greene became an Army officer, serving as sprint coach at West Point and head coach of the All-Army team. After retiring from the Army, he became a director for Special Olympics International.
In 2007, Charles Greene became the sprints coach at Lincoln Northeast High School in Lincoln, Nebraska. He coached multiple state qualifiers in his first year along with the states 3rd place 4x400 relay team of Logan Reising, Brian May, Tory Berks, and AJ Robinson.