Pestiferous molluscs are one of the biggest threats to agricultural and horticultural crops worldwide. Globally, several studies have documented the species that are pest and the loss incurred from them. In India, the surveys mainly conducted in the Northern India and several papers have published in this regard. However, there are hardly any comprehensive survey which looked at all pestiferous snails and slugs in Southern India. We conducted surveys during 2008-2010 in anthropogenic and natural habitats to document the distribution of native and introduced malacofauna in the Bangalore region (12.97°N 77.56°E, Southern India. The snails and slugs identified during the survey include Achatina fulica (Bowdich), Ariophanta solata (Benson), Macrochlamys indica Godwin-Austen, Laeviculis alte (Ferrussac), Mariaella dussumierei (Gray) and Deroceros leave (Muller). Among these the marsh slug, Deroceros leave (Muller) is a first time record from Southern India. The potential costs of these species on agriculture or the environment are largely unknown, but potentially immense.