The paper describes a method of determining hydraulic conductivity of soil in situ as a function of depth and water content for non-swelling soils in which the moisture characteristics reflect the distribution of pore sizes within the soil matrix. The method requires a series of consecutive measurements of water-content profiles. Soil-water suction may be measured in situ or inferred from water content and moisture characteristics determined in the laboratory. Calculat ion of hydraulic conductivity requires the knowledge of evaporation from bare soil during the measurement period or periods. A rapidly convergent iterative method is described for estimating this evaporation and, therefore, of calculating conductivities. The method is illustrated for data obtained on a sandy soil at the Central Arid Zone Research Institute, India.