Field studies carried out in 1980 provide records of shore communities from five open-shore sites and six caves or pairs of caves at Lundy. The species present are listed with notes on their distribution and abundance and a broad description is given of the habitats and communities present. Two main features of Lundy shores are pointed to as of high scientific interest: the very wide range of habitats and therefore species present along a short length of coastline, and the exceptional richness of slate shores in the region of Rat Island. Lundy also has a large number of intertidal caves and these are an unusual habitat with distinctive communities present. Although the communities on Lundy shores are subject to considerable enviromental stress and therefore recovery potential after damage is probably high, some species and habitats including lower-shore organisms and some cave communities are probably susceptable to long-term damage from disturbance. Care should be taken that inappropriate development or purposeful disturbance does not affect the area of Rat Island. The south-west part of the Landing Bay, The Gates, Lametry Beach and Gannets Bay should be especially protected from oil pollution. Studies of boulder shores, caves and rock pools should be carried out in a systematic comparative manner in the future. There is a need for a very general survey and associated photographic record of Lundy shores to at least assess how adequate our description of shore habitats and communities is, and to provide a basis for recording gross change.