We describe a new species of Liotyphlops (Serpentes: Anomalepididae) from Ilha de São Sebastião, municipality of Ilhabela, São Paulo state, southeastern Brazil. The new species represents the first record of the genus throughout most of the Atlantic Coastal Forest in São Paulo state. Liotyphlops caissara sp. nov. is related to L. albirostris and L. wilderi, but it can be distinguished from the first species by having a different number of body scales, and from the latter by having a distinct number of supralabials. The new species also differs markedly in color pattern by having continuous pale cream color throughout the venter.