Objective: This study aims to assess the right ventricular systolic function in patients with systemic lupus erythematosus (SLE) using fully automated right ventricular quantification software with 3D echocardiography (3D Auto RV) and to examine the correlation between right ventricular systolic function and red blood cell distribution width (RDW). Methods: We retrospectively analyzed the clinical data of 70 patients diagnosed with SLE in the Department of Rheumatic Immunology at our hospital from September 2022 to July 2023. Patients were categorized into three groups based on pulmonary artery systolic pressure (PASP): group B (PASP ≤ 30mmHg), group C (30mmHg < PASP < 50mmHg), and group D (PASP ≥ 50mmHg). Additionally, 25 healthy controls matched for sex and age during the same period were selected as group A. All subjects underwent echocardiography and blood routine examination. Demographic variables including sex, age, body mass index (BMI), and body surface area (BSA) were recorded. Two-dimensional echocardiography provided measurements of left ventricle ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic peak velocity (S'), and right ventricular area change rate (RVFAC). Measurements obtained by 3D Auto RV software included right ventricular end-diastolic volume index (EDVi), right ventricular end-systolic volume index (ESVi), right ventricular stroke volume (RVSV), right ventricular ejection fraction (RVEF), longitudinal strain of the right ventricular free wall (FWLS), and longitudinal strain of the interventricular septum (SLS). One-way ANOVA was used for intergroup comparisons. Spearman correlation analysis assessed the relationship between RDW and right ventricular systolic function parameters. Multiple linear regression was performed to analyze the influencing factors of right ventricular systolic function. Results: Compared to group A, both groups B and C showed significantly decreased RVFAC in group D, with significantly increased EDVi and ESVi. RVEF and FWLS were significantly decreased in groups C and D compared to groups A and B. Additionally, SLS was significantly decreased in groups C and D compared to group B. RDW levels were significantly higher in groups B, C, and D compared to group A (all P < 0.05). Spearman correlation analysis revealed positive correlations between RDW and EDVi as well as ESVi (r = 0.211, 0.251, all P < 0.05), and negative correlations with RVEF, FWLS, and SLS (r = -0.284, -0.247, -0.251, all P < 0.05). Multiple linear regression analysis identified RDW (β =-0.704, P=0.042) and PASP (β =-0.190, P=0.000) as independent influencing factors of RVEF. Conclusion: 3D Auto RV facilitates early detection of right ventricular systolic function impairment in SLE patients. There exists a negative correlation between RDW and right ventricular systolic function, with increased RDW and PASP serving as independent influencing factors for decreased right ventricular systolic function.