In this Note, we investigated the turbidity ratio method for the evaluation of water-in-oil emulsion stability. The slope of turbidity ratio of water-in-oil emulsions with time was taken as an index of stability; the higher the slope, the less stable the system. Various factors affecting the stability of emulsion such as HLB of emulsifier, amount of emulsifiers, and water were tested using this technique. The results of the turbidity ratio technique for the evaluation of emulsion stability were well consistent with those obtained by the measurement of phase separation when incubated for 30 days at room temperature.