Data on the diets of harbour seals (Phoca vitulina) from two islands in the Inner Hebrides (Scotland, UK) based on collections of faecal samples made in 1993 and 1994 are presented. The diet included a range of fish and cephalopod species, of which the most important were gadoids, particularly whiting (Merlangius merlangus), along with pelagic scad (Trachurus trachurus) and herring (Clupea harengus). There were significant temporal and spatial (between-island) differences in diet. The relatively high importance of pelagic species and the low importance of sandeels (Ammodytidae) is consistent with previous studies on grey seals (Halichoerus grypus) in the Inner Hebrides but differs from studies based in other parts of Scotland.