Algal habitats and communities on the chalk cliff coastline of Kent and Sussex were assessed by direct observation. Summarised accounts of the main observations are presented. Due to the geological characteristics of upper chalk, habitat and algal communities are best developed on the Isle of Thanet. Communities are relatively rarely present elsewhere in Kent and Sussex. However, only 8% (less than 2 km) of the Thanet coastline remain as natural chalk cliff. Because of the unique algal vegetation, it is strongly recommended that the remaining lengths of natural chalk cliff habitat be assigned conservation status and further coastal development be strongly opposed.