Offensive midfielder who also plays as a striker.

After playing for Academica from 2008 to 2010, Tiero switched countries to Bulgaria where he signed for CSKA Sofia but was back in Portugal to play the latter half of 2010/11 season at Olhanense. Tiero then moved to Saudi Arabia to join former Ghana coach Mariano Barreto at Al Quadisiya featuring in 15 games and netting one goal in the 2011/12 season.
Now he’s back in Portugal after joining Gil Vicente FC on a one year deal with an option to extend it by another year.

During the time of Mariano Barretos (ex-Maritimo) as coach of the National Team, Tierro was a very important part of his tactical play. Tierro was at the Olympic games as one of Ghana's 3 overaged players and scored an important goal in the second game against Paraguay. He equalized and was on hand to pass to Captain Appiah for Ghana to win that game.
Website: www.williamtiero.com
Aug 2010: Bulgarian top club CSKA Sofia have signed William Kwabena Tiero from portuguese side Academica Coimbra on a two years contract until 2012.