The EC (electrical conductivity), pH and concentrations of major anions, cations and dissolved silica were determined in the stream meltwater draining from the glacier. Stream meltwater samples were sampled during June and October 1997 from Dudu glacier, Bhngirathi valley, Garhwal Himalaya. This study is an attempt to reveal the hydrochemical processes operating in the glacialized regime of Garhwal Himalaya. The results show that the abundance order of cations and anions in the meltwater is c(Ca2+ )>c(Na+ )>c(Mg2+ ) >c(K+ ) and c(SO42- ) >c>(HCO3-) >c(NO3- ) >c(CI- ). The rock weathering is the most important mechanism controlling the water chemistry in the basin. Pyrite oxidation and carbonation are the main hydrogen ion supply reactions contributing to the chemical weathering in the basin. There is a distinct difference between the solute concentrations in samples collected during June and October. The EC (electrical conductivity), pH and concentrations of major anions, cations and dissolved silica were determined in the stream meltwater draining from the glacier. Stream meltwater samples were sampled during June and October 1997 from Dudu glacier, Bhngirathi valley, Garhwal Himalaya. study is an attempt to reveal the hydrochemical processes operating in the glacialized regime of Garhwal Himalaya. The results show that the abundance order of cations and anions in the meltwater is c (Ca2 +)> c (Na +)> c (Mg2 +)> c ( The rock weathering is the most important mechanism controlling the water chemistry in the basin. Pyrite oxidation and carbonation are the (K) and c (SO42-)> c> (HCO3-)> c (NO3-)> c main hydrogen ion supply reactions reactions to the chemical weathering in the basin. There is a distinct difference between the solute concentrations in samples collected during June and October.