Tommy Smith has joined Queens Park Rangers for an undisclosed fee, subject to clearance from the Football League.
The 30-year-old striker made 22 appearances for Pompey after arriving from Watford last August.
His only goal for the Blues came in a 3-2 Premier League victory over Hull at Fratton Park back in March.
Smith began his career at Watford and rejoined the Hornets in 2006 after spells with Sunderland and Derby.
In his second spell at Vicarage Road he scored 28 goals in 139 appearances.