Abstract: The following species of myxomycetes are reported for the first time from Finland: Arcyria affinis Rostaf., A. globosa Schwein., Colloderma oculatum (Lippert) G. Lister, Cribraria violacea Rex, Dianema harveyi Rex, Diderma asteroides (Lister & G. Lister) G. Lister, Hemitrichia leiotricha (Lister) G. Lister, Lamproderma gulielmae Meyl., Licea castanea G. Lister, L. marginata Nann.-Bremek., L. operculata (Wingate) G. W. Martin, Physarum bitectum G. Lister, and P. gyrosum Rostaf. All the specimens of Fuligo septica sensu lato in the Finnish collections have been re-examined, and two additional species, Fuligo leviderma H. Neubert, Nowotny & K. Baumann and F. luteonitens L. G. Krieglst. & Nowotny, are recognized and illustrated. The second record of the rare species Didymium obducens P. Karst. in Finland is reported and the plasmodium illustrated. The third report of Cribraria microcarpa (Schrad.) Pers. emend. Nann.-Bremek confirms the presence of that species in Finland. The known biota of myxomycetes in Finland now includes 191 species.