Objective: This stduy was planned to assess the vena contracta (VC), flow convergence area (PISA) and jet area (JA) methods in evaluating the severity of mitral regurgitation 5MR) and to test the accuracy of a proposed algorithm using these methods. Methods: Eighty-seven patients with chronic MR were enrolled in the study. VC of < 0.3 cm, maximal MR flow rate calculated by PISA (Qmax) of < 72 cm3/sn and JA of < 4 cm2 were classified as mild MR. VC of > 0.5 cm, Qmax of > 240 cm3/sn and JA of > 8 cm2 were classified as severe MR. Whereas the values between these ranges were called to be moderate MR. The algorithm was planned as follows.: In the first step, VC width was measured. If a patient has VC = 0.3-0.5 cm, it was used Qmax in the eccentric jets and JA in the central jets in the second step. The severity of MR were considered as severe, moderate and mild for >50%, 21-49% and 20% of the regurgitant fraction calculated by the reference method (the quantitative Doppler method dopending on aortic and mitral stroke volumes), respectively. Results: The sensitivity of VC was low in difeeratiating between moderate and severe MR (63%). In eccentric jets, the regurgitant volume calculated by PISA was higher than that of reference method (70±49 vs. 59±29 cm3) and the JA was found to be less than that of cntral jets despite similar regurgitant fraction (6.8±3.2 vs. 8.5±3.3 cm2). The algorithm agreed well with the reference method and it was better than those of each three methods (Cappa coefficients 0.89 vs. 0.65, 0.63 and 0.45 for VC, Qmax and JA; respectively). The accuracies of the algorithm in discriminating between mild and moderate MR or severe and non-severe MR were high 598% and 95% respectively). Conclusions: The severity of MR can be determined accurately and simply by using VC, PISA and JA methods logether.