Sixty-six cases of rheumatic fever (RF) associated with acute rheumatic carditis (ARC) diagnosed on the basis of the revised Jones criteria (1982) were studied retrospectively (Group I) and prospectively (Group II). Echocardiography in Group I revealed anterior mitral valve prolapse (AMVP) in 28/55 cases (51%), posterior mitral valve prolapse (PMVP) in four (7%), combined anterior and posterior mitral valve prolapse (BMVP) in five (9%), aortic valve prolapse (AVP) in eight (15%), and in Group II, AMVP in nine (82%), BMVP in one (9%), AVP in six (55%). Among the prolapsed valves 40% of the mitral valves in Group I and 64% in Group II were redundant with irregular focal thickenings. In the follow-up examination, three cases without AMVP in the early stage of ARC developed AMVP later; on the other hand, AMVP was found in the early stage and disappeared later in another three. These findings suggest that overall, ARC is an important etiology of MVP and AVP in China.