Jet swelling is shown to exist when a concentrated oil‐in‐water emulsion is ejected from a capillary tube into a stagnant fluid. The jet swells up to ten times the diameter of the capillary tube depending on the shear rate in the tube and the density difference between the ejected and the stagnant fluid. The relative jet swelling increases with silicone oil concentration, decreases in silicone oil viscosity, decreases in tube diameter, and decreases in tube length. The diameter ratio (jet/tube) grows as the 1/3 power of the wall shear stress in the capillary tube. The analogy between the swelling behavior of these emulsions and that observed in dilute and semidilute polymer solutions is discussed.