The miscibility and complexation behaviour of two isomeric tertiary amide polymers, poly(N,N-dimethylacrylamide) (PDMA) and poly(2-ethyl-2-oxazoline) (PEOx), with poly(styrene-co-allyl alcohol) (SAA) containing 4.5 and 6.5 wt% of hydroxyl groups has been studied. PDMA and SAA form complexes from methyl ethyl ketone (MEK) solutions when the PDMA contents in the feed are not more than 50 and 75 wt% for SAA(4.5)/PDMA and SAA(6.5)/PDMA, respectively. However, they do not form complexes from tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) solutions. On the other hand, PEOx does not form complexes with SAA from any of the three solvents used. We have previously reported that another isomeric tertiary amide polymer, poly(N-methyl-N-vinylacetamide) (PMVAc), can form interpolymer complexes with SAA from MEK solutions over the entire feed composition range and from THF solutions when the feed is rich in SAA. These observations show that the abilities of the three isomeric tertiary amide polymers to form complexes with SAA are in the order of PMVAc > PDMA > PEOx. FTi.r. spectroscopy studies demonstrate that intermolecular hydrogen bonding interactions contribute to the miscibility and complex formation in these blends.