The defender spent the past six seasons with Barcelona, making 125 La Liga appearances and having to battle serious illness during his final two seasons with the club.
|3/1||Monaco are 3/1 with BetVictor to win Ligue 1
“I am very happy to return to Monaco because this is where I started at 19,” he told reporters.
“I want to thank the president and the leaders of the club for trusting in me. It was difficult for them after doubts surrounding my physical condition.
"Monaco are not a great club of the future, they were already a great club with great players when I was there 13 years ago. Also, they did not play in the Champions League final [in 2004] by chance."
The defender is Monaco’s ninth signing this summer, joining the likes of Jeremy Toulalan, Radamel Falcao, James Rodriguez, Joao Moutinho and Ricardo Carvalho.
Abidal added: “Ricardo Carvalho played for Real Madrid and Falcao for Atletico Madrid when I was in Barcelona; but the key thing is that Falcao is a great player - he was not wrong in coming here.
“We will do everything to help him score goals. The objective is to win Ligue 1 and qualify for the Champions League.”