Second-half goals from Simon Church and Adam Le Fondre ended Reading's four-match losing streak while Doncaster remain rooted to the foot of the table.
Reading started brightly, with Jimmy Kebe forcing Neil Sullivan in the Doncaster goal into an early save.
Having squandered an early one-on-one Church made up for it tapping in from close range after Sullivan's fumble.
Le Fondre doubled their lead after heading Joseph Mills' cross home for his first goal for his new club.
Doncaster rallied a little late on, with James Coppinger firing against the post, but it was an isolated moment in a display of comfortable control from Reading.
The result leaves Doncaster still searching for their first league victory while Reading earned only their second win of the season, moving up to 14th in the Championship.