M. Kessler (Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Abteilung für Systematische Botanik, Untere Karspüle 2, D-37073 Göttingen, Germany; 106606.464@compuserve.com), A. R. Smith (University Herbarium, 1001 Valley Life Sciences Bldg., #2465, University of California, Berkeley, CA 94720-2465, U.S.A.; arsmith@uclink4.berkeley.edu) & M. Sundue (The New York Botanical Garden, Bronx, NY 10458-5126, U.S.A.; msundue@nybg.org). Notes on the genus Polystichum (Dryopteridaceae) in Bolivia, with descriptions of ten new species. Brittonia 57: 205–227. 2005.—We describe ten new species of Polystichum (Dryopteridaceae, Pteridophyta) from Bolivia, provide brief notes on the other eleven species of the genus in the country, and present a key to all species. New species are: P. albomarginatum, P. amboroense, P. bachii, P. chaparensis, P. congestum, P. giganteum, P. lepidotum, P. paramicola, P. rufum, and P. solomonii.