Polycarbonate (PC) is linear polyester of carbonic acid and diols, containing carbonate units. Recycling of the relatively higher priced polycarbonat (PC) offers economy to processors, only if the recycling does not significantly affect performance of material in terms of flow and mechanical properties. For practical applications, mostly aromatic polycarbonates produced by polycondensation of bisphenol A and phosgene are used. Polycarbonate has superior mechanical (including high impact strength), thermal (including very low thermal expansion in a wide temperature range), electrical and optical properties. Therefore, it is considered as a constructional material, used in important applications such as airplane cockpits, bullet-proof windows, astronaut helmets, medical equipment and construction parts, as well as in electrical and electronic engineering. Several studies have been conducted to understand the effect of multiple injection moulding of polycarbonate. The experiments have revealed that with an increase in the number of injection mouldings, the tensile strength of PC initially rises slightly (after the first and second processing procedure) and, then, it remains constant. The other quantities, determined in a tensile test, i.e., tensile stress at break, tensile strain at tensile strength, tensile strain at break, and longitudinal modulus of elasticity do not essentially change. The melt flow rate (MFR) increases as the number of injection mouldings of PC rises. The largest increase, being above 6% in relation to the original PC, occurs after the first processing procedure. After the sixth injection moulding, the MFR value increases by more than 13%. The glass temperature does not vary with the number of injection mouldings and is 145°C. In all the studied samples, PC does not crystallize from the liquid phase and the process of cold crystallization does not occur. The extrapolated temperature of the onset of thermal degradation, thermal degradation temperature, and temperatures corresponding to the 5 and 50% mass loses of the samples decrease by 7°C after the first injection moulding of PC. These temperatures do not considerably vary after the next five procedures. These experiments conclude that it is possible to recycle PC without losing its performance. Only some changes in processing temperatures profile would be required to compensate for degradation. (Source: Archives of Materials Science and Engineering, Vol. 37 /Issue 2- Effect of Multiple Injection Moulding on Some Properties of Polycarbonate)