The diversity of Haminoea Turton & Kingston, 1830 snails is poorly understood in the Indo-West Pacific. These gastropods occur in shallow subtidal and intertidal areas usually associated with algae, seagrass, or coral reefs, and one species, often identified as Haminoea fusca (A. Adams, 1850) is regarded to be restricted to mangrove habitats. In this paper we provide the first detailed description of this species by means of anatomical dissections, scanning electron microscopy, and DNA barcodes. A Bayesian COI gene tree including specimens from Pakistan and the Philippines together with other Indo-Pacific and Atlantic lineages was inferred and the possible existence of more than one species under the name H. fusca is highlighted and discussed. In Pakistan Haminoea cf. fusca was found to inhabit tidal estuarine mud-flats with oyster reefs.