Abstract. Isolated rupture of the popliteus muscle seems to be extremely rare. with only two cases described in the English literature. We present two cases of magnetic resonance imaging-verified isolated rupture of the popliteus muscle in polo players with the same injury mechanism—external rotation trauma on a flexed knee. Functional testing of the poplitcus musele in the figure of four position was positive in both cases. Full recovery was observed after 6 weeks of physiotherapy.