The pair who founded RIM will be replaced by Thorsten Heins, a chief operating officer who joined RIM four years ago from Siemens AG, RIM said.
Balsillie and Lazaridis have headed Waterloo, Ontario-based RIM together for the past two decades.
The once-iconic Canadian company has suffered a series of recent setbacks and has lost tens of billions in market value.
RIM said last month that new phones deemed critical to the company's future will be delayed until late 2012. And its PlayBook tablet, RIM's answer to the Apple iPad, failed to gain consumer support, forcing the company to give it deep discounts to move the devices off store shelves.
A widespread outage also frustrated tens of millions of BlackBerry users in October.
Lazaridis will take on a new role as vice chairman of RIM's Board and chairman of the board's new innovation committee. Balsillie remains a member of the board.