Accurate and reliable methods to assess fetal cardiac function would be useful in evaluating fetuses with cardiac disease (structural or otherwise). Traditionally, two-dimensional echocardiography has been used to estimate fetal ventricular volume, and assess cardiac function. However, the unique and complex geometry of the fetal ventricles makes analysis of cardiac function using this modality a challenge, and hence, the interest in using three- and four-dimensional ultrasound. Although theoretically appealing, three-dimensional echocardiography had to overcome several difficulties, including: gating, suboptimal image quality, and lack of real-time observation. Four-dimensional fetal echocardiography is a method to assess ventricular volume and cardiac function, and can overcome many of the pitfalls of conventional methods. Thus, this modality offers an important method for the assessment of fetal cardiac function.