Neymar had left Barcelona in August 2017 and claims that the former club owes him 43.6 m euros in loyalty bonuses, BBC reports.
Shortly after the transfer, Neymar filed the lawsuit, he may appeal the decision whereas a judge ruled in favor of La Liga’s side.
Barcelona said that they “widely respected” the decision and “continue to protect its legitimate interests”.
After Barca refused to pay him in 2017 after his move of 222 million euros (£200 m), Brazil forward also made a complaint with world governing body Fifa.
In addition to not paying Neymar, Barcelona started court action against him to pay back £8 m he got when he signed a new contract in 2016 with them.
FIFA had taken no action, saying that it would leave the case to the courts.