BBC reports, Neymar claims that he due to receive 43.6 m euros in loyalty bonuses from Barcelona, a club which he left in August 2017.
A judge ruled in favor of La Liga’s side but Neymar, 28, who filed the lawsuit shortly after the transfer, may appeal the decision.
Barcelona said that they “widely respected” the decision and “continue to protect its legitimate interests”.
After Neymar’s move of 222 million euros (£200 m), Barca refused to pay him in 2017 later to that Brazil forward registered a complaint with world governing body Fifa.
Barcelona started court action against Neymar to pay back £8 m he got when he signed a new contract in 2016 with them, instead of paying him.
FIFA had taken no action, saying that it would leave the case to the courts.