City goalkeeper David James was responsible for Forest seeing their run without a goal extended to five matches, the former England international rolling back the years with two outstanding saves to deny Marcus Tudgay in each half at Ashton Gate on Saturday.
City dominated possession but could not manufacture a breakthrough. The Robins have now failed to beat Forest in the last 30 meetings stretching back to December 1974.
On-loan midfielder Stephen Pearson was recalled to the City side along with defender Lewin Nyatanga.
Pearson was ineligible against his parent club Derby last weekend but was restored to Derek McInnes' starting line up at the expense of Kalifa Cisse. Nyatanga replaced James Wilson.
Dexter Blackstock made his first start for Forest following a year out with a serious knee injury. The striker, who made his comeback as a second-half substitute against Crystal Palace last weekend, replaced Garath McCleary.
Elsewhere for the visitors, Lewis McGugan came in for the suspended Guy Moussi and Joel Lynch for the injured Wes Morgan.
City started well and Pearson saw a shot deflected narrowly wide following good work by Nicky Maynard down the left-hand side.
McGugan responded for Forest with a dip of the shoulder and an effort from outside the area which worked James.
Forest lost Lynch to injury after 22 minutes so Brendan Moloney was introduced by Cotterill.
Soon afterwards James was called into action again to stop another long-range attempt, this time from Radoslaw Majewski. The former England goalkeeper then brilliantly got down to his left to keep out a half-volley from Tudgay.
At the other end, Martyn Woolford tried his luck from 25 yards but his shot went wide.
Woolford went close 10 minutes into the second half and perhaps should have scored after getting on the end of Cole Skuse's cross six yards out.
Forest keeper Lee Camp produced a superb double save just after the hour mark. Camp parried Marvin Elliott's shot from the edge of the box and the Northern Ireland international quickly got to his feet to block another effort from Albert Adomah.
Luke Chambers headed wide from a Greening corner midway through the second half before James athletically tipped Tudgay's goalbound header over the crossbar.
Nyatanga and Blackstock both had chances to win it for their respective teams in stoppage time but both players fired over the crossbar.