The only goal of a poor quality game came from Reading's Republic of Ireland international Kevin Doyle in the 63rd minute.
Skipper Graeme Murty sent in a cross from the right, Derby's Steve Howard got his head to the ball but could only flick it on to Doyle, who scored with a precise header.
Reading had much the better of a poor first half but Doyle's effort was one of three missed chances, and they also had two penalty appeals turned down by referee Lee Mason.
Their first miss came after just three minutes when a swift interchange between Dave Kitson and Doyle set up a chance for Stephen Hunt who sent his shot way over the bar.
Derby, who have now failed to score or collect a point away from home this season, were restricted to long-range efforts with Matty Oakley shooting well wide and Andy Griffin coming a little closer with his effort.
The last time Mr Mason officiated at Reading, he saw the home side put six past West Ham.
This time he seemed determined not to give them the same chance, with Derby twice getting the benefit of the doubt when the ball struck arm inside the penalty area.
This was Steve Coppell's 199th game in charge of Reading and he celebrates four years at the club on Tuesday.
This much-needed win will make the occasion a little happier for him.
Now both clubs have a two-week break before facing away trips - Reading to Blackburn and Derby to Fulham - as they continue their fight for Premier League survival.