Ternary blends of polyarylate (PAr), polyamide-6 (PA-6) and PAr-PA-6 block copolymer were prepared by the dissolution/recipitation method or by melt blending. The compatibilizing effect of PAr-PA-6 block copolymer was observed with scanning electron microscopy and differential scanning calorimetry. The inward shift of the glass transition temperature (T-g) of PAr and PA-6 and the depression of the melting temperature (T-m) of PA-6 in ternary blends depended on the block length as well as on the amount of the block copolymer added. The shorter block length and the higher amount of block copolymer added caused greater shifts of T-g and T-m. The compatibilizing effect of the block copolymer was also confirmed from the enhanced mechanical properties.