During her 33-year head coaching career, Grentz has accumulated over 670 wins. While at Rutgers she won 434 games, including an AIAW National Championship in 1981. She also reached the NCAA Tournament in nine consecutive seasons with the Scarlet Knights. During her time at Illinois, Grentz won 210 games and reached the NCAA Sweet Sixteen twice. In 1992 Grentz was the US Women's Basktball Olympic team head coach, leading the US to a bronze medal.