The New Zealand international will remain with the Championship side until January 1 after impressing manager Kenny Jackett with an impressive seven goals in 12 appearances
The 20-year-old, who joined Kenny Jackett's side on an initial two-month deal on September 17, has notched an impressive seven goals in 12 games, including the winner in Sunday's 1-0 win over Leeds United on Sunday as the Lions stretched their unbeaten run to 10 games.
West Brom, however, currently sit fourth in the Premier League after a shock 2-1 victory over Chelsea on Saturday and, with 19 goals scored already this season, Wood has been deemed surplus to requirements at The Hawthornes.
A statement on the club's official website read: "The club are pleased to confirm that Chris Wood's loan spell at The Den has been extended until January 1."
Following the win over Leeds, Jackett told Sky Sports: "We've been pleased with Chris, he's worked hard in the group and if as a centre-forward you can get in the habit of popping up with a winner, that's great. We've been very pleased."