In this work, for the first time, organic gas steam-liquid extraction (OGS-LE) technique was developed as a promotion in the liquid-liquid extraction (LLE) method, by the use of a special homemade extraction cell that was designed to facilitate the traditional LLE method, without emulsification and with high extraction efficiency by a small amount of organic solvent in one step. This method is fast, simple and efficient, and was employed for the selective extraction and determination of cobalt (II) from water samples. The efficiency of the OGS-LE method was compared with the LLE method. The obtained results revealed that by using the OGS-LE technique, the extraction efficiency of cobalt from a synthetic mixture was over 90%, much higher than the traditional LLE method (34%).