Poly(p-xylylene) (PPX) and its derivatives were prepared by vapor-phase pyrolysis and subsequent chemical vapor deposition (CVD) of the pyrolysis products. Readily available esters of alpha,alpha＇-dihydroxy-p-xylylenes were utilized as starting materials. Mechanistical studies prove that 1,4-quinodimethane is formed by pyrolysis of diesters. The PPXs obtained compare well to PPXs obtained by the classical route using [2.2]paracyclophanes. C-13 CP-MAS NMR spectroscopy indicates that the arrangement of substituents along the polymer main chain is controlled by the size of substituents.