Despite the Hammers' poor start to the season Zamora's individual form has seen him score 5 times in 7 games.
Zamora told the official site, “I'm delighted to have extended my contract and I'm now looking forward to spending my long-term future at Upton Park.
”I've been here for almost three years now, and there is really no other place I would rather be. This is my Club and wearing a claret and blue shirt is all I have ever wanted to do.
”Personally, the season has started well for me and, although results haven't been great recently, I'm confident that the team will get back to winning ways soon.
”The spirit among the squad is still excellent and we are all working hard to turn things around. As long as we stay focused and believe in ourselves, I'm sure the results will come soon.”