Bobby has been the head baseball coach at Francis Howell North High School since 1986. His teams won eight league titles, six district championships, four sectional titles and two quarterfinal championships.

In 2001 and 2002, his team finished second in the Missouri State Tournament. Dunahue was named Gateway Athletic Conference Coach of the Year in 1998, 2000 and 2001. He was the St. Louis Post-Dispatch Coach of the Year in 2008 and 2009.