A total of 46 different species of marine algae was collected in Guatemala, 11 species of the Cyanophyta, 11 Chlorophyta, 1 Phaeophyta, and 23 Rhodophyta. Only Enteromorpha flexuosa and Caloglossa leprieurii were common to both coasts. A number of economically valuable phycocolloid algae were found on the Caribbean coast.