A method devised by Arnaud to evaluate the transverse coupling between dielectric waveguides has been successfully applied with a step-like approximation to two skew rectangular dielectric waveguides lying in different parallel layers, and tractable analytical expressions, which can be very useful in the analysis and the design of the waveguides, have been obtained. The mode power along one of the guides when the other is excited has been calculated and the results compared with experimental results appearing in the literature. The agreement is in general quite satisfactory.