Regioregular and regiorandom analogues of a dialkoxy-substituted poly (1,4-phenylene ethynylene) (PPE) bearing a pair of dissimilar side chains (dodecyloxy and methoxy) on each ring have been prepared to explore how the relative placement of substituents (see figure) can be used to modify the properties of this class of conjugated polymers. A preliminary study of the effect of regioregularity on properties is presented in which regiorandom and regioregular polymers are compared.