The paper aims to analyse the energetic performances of Organic Rankine Cycles (ORCs) for biomass micro-scale CHP applications. Subcritical and transcritical cycles have been compared and the influence of internal regeneration on system behaviour has been evaluated. The investigation illustrates the noticeable influence of the operating conditions and ORC configuration on the main CHP performances. Furthermore, results reveal that the proper choice of the organic working fluid is fundamental to assure proper operations and optimise the system behaviour.The analysis shows that the transcritical cycle with internal regeneration offers the maximum electric performances, whereas the saturated cycle in simple configuration guarantees the highest thermal efficiency. Furthermore, all the investigated systems guarantee positive energy saving capabilities.