An Ethno botanical survey was carried out among the ethnic groups in the Kolli hills, Tamil Nadu, India. Kolli Hills or Kolli Malai is a small mountain range located in central Tamil Nadu in Namakkal district of India. The mountains are about 1000 to 1300 m in height and cover an area of approximately 280 km². The present study revealed that the medicinal plants are used to cure skin diseases, stomach problems, diabetes, urinary infections, fever, cough, cold, snakebites, ear ache, hair growth, headache, indigestion, itches, swellings, wounds and dental problems. Traditional medicinal uses of 60 plants species belonging to the various families were described in this study. The medicinal plant resources in Kolli hills continue to play a vital role in healthcare needs of malayali tribal community. The traditional knowledge of local tribal people on medicinal plants was collected through questionnaires and personal interview of local traditional practitioners during field trips. The elder generation has sound knowledge about medicinal plants. The collection and documentation of their practical knowledge and traditional techniques based on the traditional use of plants is a significant step towards the preservation of the valuable knowledge by keeping in view the fading ethnic traditions and cultures. From this study it is obvious that more attention need to be paid to understand and prove the efficacy of traditional knowledge on medicinal plants using advanced scientific tools.