Mpenza joins Plymouth
Plymouth manager Paul Sturrock said: "He is an international striker and they don't exactly fall off trees. He brings experience to the front-line and gives us something different to what we have had before.
"He is a big, strong boy and he has done it, seen it and got the t-shirt. He played in the Premiership 25 times last year and we are delighted to have that kind of standard here.
"His agent came to us and we have been haggling with them for a while. He has got phenomenal strength and I couldn't believe when we got the opportunity to sign him, but he is here now and we are looking forward to it."
Mpenza, 30, was released by Manchester City in July, having scored five goals in 25 appearances for the Premier League club.