The BaylisHillman reaction provides a protective-group-free strategy to heterobifunctional polyesters, which can be further modified via various post-polymerization modification reactions. This contribution explores the BaylisHillman polymerization of 1,3-butanediol diacrylate with two readily available dialdehyde monomers, iso- and terephthaldehyde. The influence of a variety of catalysts and additives on the polymerization of these two pairs of monomers and in particular the molecular weight of the resulting polymers was investigated. The presence of the orthogonally reactive vinyl and hydroxyl groups makes the polymers interesting, e.g., as precursors for dual-cure coatings.