Benjani has signed a one-year contract with the Fratton Park outfit.
“It’s great to be back,” the 33-year-old Portsmouth’s official website. “I love the Pompey fans and I’ve been thinking of them ever since I’ve been away.
“They always make you feel good. If you are down then they lift you up, so it’s good to be back.
“They gave me a great reception before the Brighton game and I love everything about them. They make me feel special.
“I found out that Pompey wanted me on Thursday and we did the deal on Friday – I didn’t have to think about it for a second because I knew I would be coming home.”
“My level of fitness still needs to improve but I’m looking forward to getting out on the pitch and playing again,” said the former Manchester City player. “The aim for me is to score goals for Pompey and help them climb the table.”