In our present investigation, we obtain the initial coeficients a2, a3, a4 and a5 for a class of univalent λ−pseudo starlike functions associated with Sigmoid function and then we find the Zalcman functional |a3 2-a5|. Specializing the parameters, we improvise Zalcman functional for the class of starlike functions and also we point out Zalcman functional for the class of functions which are product combination of bounded turning and starlike functions. © 2018, Transilvania University of Brasov 1. All rights reserved.