In 1986, Seymour was hired as a part-time assistant basketball coach at Saint Anselm College in Goffstown, New Hampshire. He became a full-time assistant in 1989. In 1991, Bill Herrion left an assistant coaching position George Washington to take-over as head coach at Drexel. Herrion added Seymour to his staff upon his arrival at Drexel, as the two had gotten to know one another on the recruiting trail. During Seymour's eight-season tenure on Herrion's staff, the Dragons won 167 games, won the America East Conference regular season title four times, the America East Conference tournament three times, made three NCAA Tournament appearances (including the program's first tournament win as a Division I program in 1996), and made one appearance in the NIT.