This article presents the summary of our investigations of liquid-crystalline polymorphism of asymmetrical 4-alkyloxybenzylidene-4'-alkyloxyanilines. The existing type of mesophases was confirmed by Sackmann-Demus miscibility method. In this paper the influence of the polarity and the structure of the mesophases standards on the topology of phase diagrams are broadly discussed. Additionally we present X-ray investigations of two derivatives. (c) 2012 Elsevier B.V. All rights reserved.