Although large areas of relatively undisturbed forests are essential for preserving biodiversity, opportunities for conservation in human-dominated landscapes must not be overlooked. Agroforestry systems such as shaded coffee plantations are known to be more compatible with biodiversity conservation than other, more drastic, land transformations. In recent times, however, modernization of coffee cultivation has influenced its conservation values adversely. We evaluated adult butterfly diversity in 12 coffee plantations around a protected area (PA) in the Western Ghats, India. We sampled 25 transects that varied in distance from the PA and in proportion of silver oak Grevillea robusta, an exotic timber species. We also had two transects within the PA. We used a combination of line transects and fruit bait traps to sample butterflies. Micro-climatic variables (temperature, humidity and light intensity) and other habitat variables (e.g. canopy cover, tree diversity, herb species richness) were recorded for each transect. We analyzed the effect of these variables on the abundance and species richness of butterflies, overall as well as in different families, feeding guilds and size classes. Proximity to the PA significantly influenced the abundance and richness of butterflies in coffee plantations, with transects close to the PA having higher abundance and richness than transects further away. Also, in terms of butterfly species composition, similarity to forest declined with increasing distance. Among the habitat variables, only canopy cover had a significant effect on abundance and richness, and the effect was negative. These patterns, with some exceptions, were also reflected for different families and feeding guilds. The proportion of silver oak had no apparent effect on butterflies. This study demonstrates that coffee plantations can act as a buffer for butterfly fauna within a certain radius of a PA. They have great potential as auxiliary tools and can significantly complement conservation efforts that are currently centered on PAs.