In this report, we present a case of rhino-orbital mucormycosis in a 57-year-old female with poorly controlled diabetes mellitus. The only mold cultured at 25°C, 37°C, and 40°C from a specimen of the nasal crust was identified phenotypically and independently using nuclear ribosomal DNA sequence data as Thamnostylum lucknowense. To our knowledge, this report presents the first data implicating this mucoraceous fungus as a mycotic agent of human infection.