Blends of poly (amide-6) (PA) and poly (epsilon-caprolactone) (PCL) prepared by solution casting and screw extrusion have been investigated by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). From the measured melting point (T(m)) of the solution-cast PA/PCL blends, a T(m) depression of the PA was observed for the investigated compositions. No T(m) depression was found for the extruded PA/PCL blends, however. In the SEM study of the morphology of the solution-cast PA/PCL blends, phase separation was observed between the PA phase and the PCI, phase for all blend compositions. For the extruded PA/PCL blends, however, more pronounced phase separation was observed for all blend compositions. Ternary blends of PA, PCL, and bisphenol-A polycarbonate (PC) have also been prepared by screw extrusion. From the study of morphology and extrudate swell of the PA/PC binary blends and the extruded PA/PC/PCL ternary blends, it appears that PCL could be used as a compatibilizer for the extruded PA/PC/PCL blends. (C) 1993 John Wiley & Sons, Inc.