Two-time national champion Santos signed former Brazil midfielder Pedrinho on Saturday.
Pedrinho, who was without a team since being released by Fluminense last year, signed a contract until June, with Santos having an option to extend the deal until December, the club said on its Web site.
Financial details were not disclosed.
Pedrinho, 29, played in the Brazilian national team in 1998 under Vanderlei Luxemburgo, who now coaches Santos.
The midfielder was plagued by two severe knee injuries that kept him off the fields for more than a year early in his career.
Pedrinho previously played for Saudi Arabia's Al Ittihad and Vasco, where he won two Brazilian league titles, the Copa Libertadores and the Copa Mercosur.
Santos, Brazilian champion in 2002 and 2004, leads the Sao Paulo state championship with 12 points from four matches. It hosts Guaratingueta on Sunday at Vila Belmiro stadium.