Abstract: This paper deals with the three hundred or so butterflies to be found in the Nilgiri Mountains of Southern India. Special emphasis placed on placing the butterflies in perspective in relation to a number of defined ecological zones. Following a descriptive on the climate, topography and vegetation zones in the Nilgiris is a section of the history of entomological exploration. The major part of the paper is devoted to a summery account of each species known to occur in the Nilgris. Every attempt has been made to update the nomenclature which is cross-referenced to that of Wynter-Blyth (1957) whose nomenclature actually dates back to the 1930ies. Since this nomenclature is the same for most of peninsular India and since the Nilgris contain the populations of virtually all species known to occur in the southern India, the paper should also be useful out of the Specific Nilgiri context. The data included will be the basis for a later analysis of the ecological and zoogeographical nature of the Nilgiri butterflies, but some initial non-quantitative conclusion are discussed.