Stoke's record signing was given the opportunity to kick-start his season during the January transfer window but chose to wait for a move back to the Madejski and is raring to go after signing until the end of the season.
Kitson told the club's official website: "I had opportunities to go out on loan from Stoke in January but in my mind I was waiting to see if Reading came in.
"A lot of people have moved mountains to make this move happen and I am very grateful to be back.
"We are sitting third but if we win our games in hand we'll be in a nice position. All the top teams have faltered and it's time to kick on and make it happen."