Purpose <p>This study was conducted to investigate the diagnostic characteristics of uncommon manifestation of Ebstein Anomaly (EA) during the fetal period, to improve the accuracy of prenatal diagnosis.</p> Methods <p>This retrospective analysis was conducted with data from fetuses diagnosed with an uncommon manifestation of EA between January 2020 and October 2024. Maternal and fetal information, prenatal ultrasound data, and information on pregnancy termination/delivery and postnatal surgical treatment were collected.</p> Results <p>The sample comprised 13 with isolated posterior leaflet displacement and 1 with all tricuspid valve leaflets displaced. Four children (two with additional displacement of the septal leaflet detected by postnatal ultrasound) survived. The ultrasound features of isolated posterior leaflet displacement were: (1) normal positioning of the septal and anterior leaflets and significant tricuspid regurgitation with a low starting point of the regurgitant jet on four-chamber view, (2) non-parallel orientation of the line connecting the posterior and anterior leaflet attachment points to that connecting the superior and inferior vena cava on bicaval view, and (3) common association with pulmonary artery stenosis or atresia. Characteristics of the displacement of all leaflets were: (1) downward displacement of all valve leaflets with disruption of the continuity between the septal leaflet and coronary sinus wall, and (2) location of the displaced tricuspid valve orifice at or below the mid–left ventricular level, preventing visualization of the mitral valve, on low short-axis view.</p> Conclusion <p>The ultrasonic characteristics summarized here enable the accurate prenatal diagnosis of uncommon manifestation of EA. Isolated posterior leaflet displacement may evolve with other morphological anomalies, necessitating regular monitoring.</p>