The objective of this work was to determine the diversity and abundance of the polychaete worms of an area of intertidal zone of the Bay of Bique, Pacific Panama.  From January to June of 1995, 3,555 polychaetes belongs to 24 taxonomic groups (total sampling area: 0.748 m2, sieve of 1.0 mm). The density average was 4,884 individuals/m2 , with range from 386 to 15,045 individuals/m2. The abundance varied significantly among sampling dates. The diversity (H’) oscillated between 0.68 and 2.28 by date. The evenness varied from 0.37 to 0.89. A difference was found for H’ among the rainy and dry seasons. The environmental parameters studied did not have effect on the polychaete community structure of Bique Beach which probably is regulated by biotic factors (predation and/or competence). Nevertheless, environmental factors may have interactive additive effects over the temporal changes observed on the benthic community.