The Kaldárholt field is an important low-temperature geothermal fields located in S-Iceland. This field has been exploited from 2000, used mainly for heating purposes. Available well logging data (temperature profiles, dual neutron logs, natural gamma ray and caliper logs) as well as acoustic televiewer and production history data, were analyzed in an attempt to estimate reservoir parameters and identify possible fracture systems in the study area in relation to the different rock units and feed zones. The interpretation of temperature data shows that there is an oriented upflow of water with a temperature of 67°