Disorders of development, fusion, or resorption of paired Müllerian ducts give rise to a number of congenital uterine anomalies. Three-dimensional ultrasound remains the gold standard for diagnosing and classifying uterine shapes. A correctly obtained coronal plane of the uterus enables accurate measurements and serves as the foundation for implementing subjective and objective criteria across all major classification systems. This chapter describes the procedures, techniques, modes, and image enhancements that facilitate the diagnosis of Müllerian anomalies with three-dimensional ultrasound.