The work is expected to be a requiem for orchestra, chorus and soloists lasting between 40 and 50 minutes.
The competition is open to composers in the 18 to 35 age bracket. The deadline for submitting the scores is May 31.
The winning composition will be premiered in Gdańsk in November.
The Westerplatte peninsula is where the first shots of World War II were fired on September 1, 1939, with the Battle of Westerplatte commemorated annually as the first clash between Polish soldiers and invading German forces.
The former Polish Military Transit Depot at the Westerplatte peninsula has recently been the site of archeological research by the Gdańsk-based Museum of World War II.
In the course of the project, the remains of nine Polish soldiers have been discovered. Five of them have been identified. A burial ceremony is planned for the autumn at a military cemetery in the area.
(mk/gs)