PC/ABS blends, encompassing the whole composition range between PC and ABS, were prepared by a Brabender-like apparatus and compression molded in sheets. The analysis of processability, confirming the improved PC processability by ABS additions, was accomplished by the same apparatus used for the blend preparation. A DSC investigation confirmed the inward Tg shift found by other authors. Two very different mechanical tests were performed: (a) tensile stress-strain on unnotched specimens at a very low deformation rate, showing a decreased PC ductility in blends with ABS additions; and (b) flexural impact tests (Charpy model on sharply notched specimens at a very high deformation rate, where a strong synergistic effect was detected in a restricted composition range (20-30% ABS). A comparison of the experimental data of the Young＇s modulus versus blend composition with the Kerner＇s model predictions confirmed the good adhesion existing between PC and ABS domains. The results were interpreted on the hypothesis of interlayer zones existing at the PC/ABS boundary.