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The appearance of swirl in the fluid flow, without any external factors, is named self-rotation. There is no consensus among the researchers on the possibility of self-rotation in sink flow. In the present study, this phenomenon is studied experimentally and numerically. In the experiment, a new setup is proposed and the thymol-blue method is developed for velocity measurement. The experimental results show that the net value of circulation in the flow domain does not increase relative to its inlet value with increasing drain flow rate up to several times of claimed critical value. In other words, self-rotation does not happen in sink flow. In the numerical study, the three-dimension model of the experiment is simulated under the same conditions with the experiment. The simulation results have good agreement with the experiment ones and show that the self-rotation does not occur. In addition, the numerical results show that the swirl, or corresponding circulation, which was seen in the experiment, is due to asymmetry of input flow and by eliminating this asymmetry, the swirl can be removed completely.