Background: Small cavity left ventricle (SCLV) may affect the clinical outcomes of patients undergoing mitral valve replacement (MVR). This study aims to investigate the incidence of SCLV in patients with rheumatic mitral valve stenosis undergoing MVR and analyze its effect on short-term patient outcomes. Methods: We retrospectively examined all consecutive patients with isolated or concomitant MVR for rheumatic mitral valve stenosis in our center from 2013 to 2018. SCLV was defined as end-diastolic volume index ≤ 50 ml/m2. After inclusion and exclusion, a total of 1,437 patients were analyzed. The baseline information was collected and compared between SCLV and non-SCLV patients. Multivariate logistic regression analysis was conducted to determine the effect of SCLV on early mortality. Results: A total of 1,437 patients were included in the study. SCLV was detected in 13.57% of the patients. Compared with the non-SCLV group, patients with SCLV were smaller-sized and primarily female. There were no significant differences between SCLV and non-SCLV patients regarding major postoperative complications, nor were there incidence of prosthesis-patient mismatch. Logistic regression analysis showed that SCLV was not a risk factor for short-term mortality (P = 0.998). Conclusions: Our results demonstrated that SCLV was not associated with poorer early outcomes after MVR surgery in patients with rheumatic mitral valve stenosis.