A hillslope profile is a line on a land surface linking a crest on a drainage divide and a base on a drainage line, following a maximum gradient path that runs perpendicular to the contours. The idea of hillslope profiles is most easily applicable in well integrated fluvial topography, but has some relevance in most kinds of landscape. Hillslope profile determination and analysis can readily be justified as providing basic descriptive information, of academic interest and of background value in various practical applications. Agreement and standardisation are clearly advisable in order to build up a body of adequate and comparable data sets, although the variety of purposes behind hillslope survey and the variety of hillslope profiles must be recognized. Attempts to choose representative samples of hillslope profiles should recognise that selection of a set of paths on a surface is a special kind of sampling problem, which is not well understood.