Prosthesis-patient mismatch occurs when the effective orifice area of the prothesis is too small according to the patient’s body size after insertion, which may consequently result in consistent presence of significant residual transvalvular pressure gradients postoperatively, hampering the prognoses of patients. Currently the indexed effective orifice area measured by postoperative transthoracic echocardiography is considered the only appropriate parameter which can accurately describe the mismatch. Valves of various types can have very different indexed effective orifice areas, so the incidence of mismatch also varies. Recently, the mismatch following transcatheter aortic valve implantation is drawing increasing attention. The clinical implication of prosthesis-patient mismatch is still debated. Many factors, including the indices, standard and other mixing factors, together with the age, preoperative cardiac function and types of valve disease of patients can be related to the mismatch, the previous conclusions have been various. Prosthesis-patient mismatch may cause a greater influence to patients with left heart dysfunction and young patients. It can be largely prevented by choosing prostheses of appropriate size or by enlarging the aortic root by operation if necessary; a final decision should be made according to the patients’ condition. Severe mismatch and mismatch in patients with severe cardiac dysfunction should be avoided. In this paper we reviews the recent progress on prosthesis-patient mismatch.