[en] Exposures to tritiated water (HTO), organically bound tritium (OBT), and tritium gas are important concerns among occupationally exposed workers. Like HTO, OBT can enter the body through different routes of intake and can be accumulated in the body by exchanging the tritiated water (HTO) atoms to form organically bound tritium. A considerable portion of the OBT binds tightly to biological molecules, or remains as OBT in various degrees of solubility. OBT is retained in the human body much longer than tritiated water (HTO) and therefore the dose arising from OBT can reach 50% of the total tritium dose. The most widely used methods for measuring OBT are wet oxidation (with perchloric acid and hydrogen peroxide), and dry combustion. The dry combustion (Gold standard) method is the more suitable and includes oxidation of hydrogenous materials by heating in the presence of oxygen, with the combustion products passing over heated copper oxide at 590 degree C-700 degree C, that acts both as a catalyst and final oxidizing agent. This method is complicated and time consuming. We tested a simple and rapid method, similar to method used by Briot in France, to determine OBT in urine by liquid scintillation counting. The principle is based on subtracting the tritiated water phase counts from the total activity found in the soluble tritium phase (OBT+HTO) in urine. The main problems encountered when measuring total tritium (HTO+OBT) in urine are the color and chemical quenching, nonspecific luminescence due to the organic matter, and the contribution of ⁴⁰K background, which is naturally present in urine. In order to overcome these major problems we used the Quantulus 1220 LSC counter operated at Soreq NRC