Bucculatrix brunnella sp. n. is described from Sicily and Sardinia. The male of the new species is characterized by the almost monochrome ochreous brown forewing. It may resemble the monochrome form of B. cristatella (Zeller, 1839), but the colour of the forewing of the latter species is pale ochreous grey. The female of the new species is slightly smaller, paler and with more conspicuous pattern on the forewing than those of the male. B. brunnella sp. n. differs markedly in the male genitalia from other known Bucculatrix species. The immature stages are unknown. The male and female adults, and genitalia of both sexes, are figured and a distribution map is provided.