During fieldwork in Guyana several unusual and distinctive taxa of polypores were collected, three of which are described here as new. The first of these, Amauroderma coltricioides is the first species known in the Ganodermataceae with smooth basidiospores. Coltricia verrucata and Coltriciella navispora also are described as new, and a key to the neotropical species of Coltricia is provided. Finally, a checklist of 73 poroid fungi from Guyana is given, of which 29 are new records for the country.