- Source: 2003 Davis Cup Americas Zone Group III
The Group III tournament was held in the Week commencing March 31, in Port of Spain, Trinidad and Tobago, on outdoor hard courts.
Format
The eight teams were split into two groups and played in a round-robin format. The top two teams of each group advanced to the promotion pool, from which the two top teams were promoted to the Americas Zone Group II in 2004. The bottom two teams of each group were placed in the relegation pool, from which the two bottom teams were demoted to the Americas Zone Group IV in 2004.
Pool A
= Guatemala vs. Saint Lucia
== Jamaica vs. Bolivia
== Guatemala vs. Bolivia
== Jamaica vs. Saint Lucia
== Guatemala vs. Jamaica
== Bolivia vs. Saint Lucia
=Pool B
= Puerto Rico vs. Trinidad and Tobago
== Honduras vs. El Salvador
== Puerto Rico vs. El Salvador
== Honduras vs. Trinidad and Tobago
== Puerto Rico vs. Honduras
== El Salvador vs. Trinidad and Tobago
=Promotion pool
The top two teams from each of Pools A and B advanced to the Promotion pool. Results and points from games against the opponent from the preliminary round were carried forward.
Jamaica and Puerto Rico promoted to Group II for 2004.
= Puerto Rico vs. Bolivia
== Jamaica vs. El Salvador
== Puerto Rico vs. Jamaica
== Bolivia vs. El Salvador
=Relegation pool
The bottom two teams from Pools A and B were placed in the relegation group. Results and points from games against the opponent from the preliminary round were carried forward.
Guatemala and St.Lucia demoted to Group IV for 2004.
= Guatemala vs. Honduras
== Trinidad and Tobago vs. Saint Lucia
== Guatemala vs. Trinidad and Tobago
== Honduras vs. Saint Lucia
=Final standings
Jamaica and Puerto Rico promoted to Group II in 2004.
Guatemala and Saint Lucia relegated to Group IV in 2004.