In this paper the velocity distribution for multiple parallel plane jets based on the superposition of Reichardt's solution for single free jet is derived. The extend of the applicability of Reichardt's hypothesis to prediction of multiple parallel plane jets is examined. Both ventilated and unventilated two parallel plane jets data published in the literature and obtained for this study were used for comparisons with the theoretical results obtained from Reichardt's hypothesis. LDA measurements of mean streamwise velocities and turbulence characteristics of an array of 5 parallel plane jets were also made in order to establish the conditions under which this heuristic approach is valid. Results show that provided the pressure gradient in the lateral direction is small and hence the deflection of the individual jet center line is small, there is a good agreement between experimental results and predictions based on Reichardt's hypothesis for multiple parallel plane jets.