A new analytical solution for an evaporating spray in a shear layer has been developed. The possibility of flow deceleration or acceleration is also accounted for. The Stokes number is identified as a small droplet-related parameter to be used in a perturbation analysis of the liquid phase governing equations. Appropriate specification of additional parameters ensures that similarity is achieved so that the concentration field of the liquid in the spray can be readily found. Numerical results highlight the major factors that influence the distribution of the liquid phase (and, hence, the vapor) in the developing shear layer between two unidirectional gas streams flowing over one another with (the possibility of) dissimilar velocities in their respective free-streams. Copyright ® 2007 Begell House, Inc.