In 1987, Paul was one of the college players chosen to represent the Philippine National team to the ABC Youth championships held in Manila.

He then became a member of the RP Basketball team to the William Jones Cup in Taipei, the SEA games in Jakarta and ABC Championships in Bangkok.

[2] In his final year with San Sebastian College in 1988, Alvarez, along with league MVP Eugene Quilban, led the Stags to sweep the elimination round and then clinch the school's third NCAA title.

Paul Alvarez turned pro in 1989 and was drafted third overall by Alaska Milk, behind fellow national teammates Benjie Paras and Nelson Asaytono.

Helping to limit the point production of Best Import Awardee Wes Matthews in the finals against Ginebra San Miguel, Alvarez and the Milkmen won their first-ever PBA championship.