On a regional scale, some of the most profound impacts of climate change due to increases in greenhouse gases would probably be major changes in the hydrological cycle, in water availability, in agricultural production and in the use of energy. This paper gives a brief overview of studies carried out on climate change and possible impacts on hydrology and water resources in India, covering also the agricultural aspect. The need is emphasized for carrying out further studies in this important subject area at the national level, keeping in view the data and computing facilities available.