Abstract: Deals with deforestation, its causes and related to environmental problems in southern sector of Western Ghats. The deforestation trend from 1905 to 1973 is assessed by means of topographical maps and Landsat Images. It is also reported that the natural vegetation has decreased from 44% in 1905 to 17% in 1973. Field studies in a representative area indicated that deforestation continues unabated. Bearing in mind a rate of over 5% deforestation over a period of 11 years (1973-84), it is estimated that only 9-10 percent of the total geographical area of the state remains under a natural vegetation cover, with an intact forest ecosystem. With such an alarming rate of deforestation, this region once famous for tropical rain forest, is now left only with only a few pockets of virgin rain forest along the rugged slope. As a number of factors are involved in the deforestation and also in the qualitative degradation of the natural forest ecosystem. Problems such as soil erosion, landslides channel siltation, etc are occur through out the study area. This study attempts to highlight the deforestation trend, and its associated causes and effects, so that this grave problem can be properly understand.