Liquid-crystalline properties of the homologous series of 4-octyloxybenzylidene-4'-alkyloxyanilines are described. Based on the polarization microscopy (POM and TOA methods) and the calorimetric (DSC) measurements a rich polymorphism was detected. Investigated compounds exhibit nematic, smectic C, smectic I and smectic G mesophases with their characteristic configurations. The presence of all mesophases was confirmed by the miscibility method, using 4-heptyloxybenzilidene-4'-pentylaniline (1), 4-octyl-4'-decyloxyazobenzene (11) and 4-octyl-4'-undecyloxyazobenzene (111) as the mesophase standards. The influence of an alkyl chain length on the mesophase sequence and the entropic effects are extensively discussed. (C) 2009 Elsevier BY. All rights reserved.