Water quality of Himalayan rivers has been steadily deteriorating over several decades due to anthropogenic activities, dumping of treated or untreated effluents, poor structured sewerage and drainage system, etc. In the present study, the water quality of five important rivers namely, Gola, Kosi, Ramganga, Saryu and Lohawati rivers were investigated which flow through the different districts of Kumaun region of Uttarakhand Himalaya. The water of all these rivers serves as the major source for drinking and irrigation purposes in these districts of the Kumaun region of Uttarakhand. River water samples collected in pre-monsoon and post-monsoon seasons of the years 2011 and 2012 were analyzed for various water quality characteristics. Statistical analyses indicate positive correlation among most of the chemical parameters. Piper diagram illustrates that all the water samples fall in Ca–Mg–HCO3 hydrochemical facies, Moreover, the suitability of water for drinking purposes determined by water quality index indicated that river water in both the seasons is unsuitable. Irrigation water quality of all the river water was found suitable during both the seasons according to the result of sodium adsorption ratio, sodium percentage and residual sodium carbonate. The present study revealed that major factors contributing to deterioration of water quality of all the rivers might be eutrophication, tourism, anthropogenic and geogenic processes. Therefore, to restore the vitality and water quality of all these rivers, proper water resource planning programme should be developed.