Frank's dismissal came before the Nets' 17th consecutive loss this season, a 106-87 drubbing by the Los Angeles Lakers. The loss tied an NBA record for the most defeats to start a season.
Tom Barrise, an assistant coach, was named interim coach while the team looked for a permanent replacement for Frank.
Frank became the Nets' head coach in 2004 after serving as interim coach for several months.
"I want to thank Lawrence for his more than a decade of service to the Nets, first as an assistant coach and then as the head coach for the past 6 1/2 seasons," Nets President Rod Thorn said.
The Nets had made the playoffs four straight years but had losing records each of the past two seasons.
Frank's career record is 225-241.