We analyzed gas samples collected from fumaroles and bubbling pools at Irruputuncu, Putana, Olca and Alitar volcanoes located in the central Andes volcanic zone (northern Chile). The Irruputuncu and Putana fumarolic discharges showed outlet temperatures ranging from 83 degrees C to 240 degrees C and from 82 degrees C to 88 degrees C, respectively. The chemical and isotopic (He-3/He-4, delta C-13-CO2, delta O-18-H2O and delta D-H2O) compositions of these discharges were similar to medium-to-high temperature volcanic gases from other active volcanoes in this sector of the Andean volcanic chain (e. g. Lascar volcano). Inorganic and organic gas geothermometers for the H2O-CO2-CO-H-2, CO2-CH4 and C-2-C-3 alkenes-alkanes systems indicated equilibrium temperatures that exceed 500 degrees C at the gas sources. These relatively high temperatures are in agreement with the presence of relevantly high concentrations of magmatic gas emissions, including SO2. Olca and Alitar volcano fluid chemistries indicated lower amounts of magmatic-derived gas species, while both the helium and the water isotopic compositions suggested significant fractions of shallow, crustal/meteoric-originated fluids. These indicate contributions from a hydrothermal environment with temperatures <400 degrees C. The geochemical and isotopic features derived from the present study show that the Irruputuncu, Putana, Olca and Alitar volcanoes should be considered as active and thus warrant periodic geochemical monitoring to determine the evolution of these systems and their potential hazards.