We describe a new species of dwarf chameleon from the Brookesia minima species group. Brookesia tedi sp. n. occurs above 1300 m above sea level on the Marojejy massif in northeastern Madagascar. It is genetically sister to B. peyrierasi, a species occurring in lowlands around the Baie de Antongil, but is genetically strongly divergent from that species in both nuclear (c-mos) and mitochondrial (16S, ND2) genes, and morphologically in its smaller size and distinctly different hemipenis. It is the second species of the B. minima species group from Marojejy National Park, but is not known to occur in syntopy with the other species, B. karchei, due to elevational segregation.