The development of the molten carbonate fuel cell (MCFC) technology at Ansaldo Ricerche (ARI) is reported, starting from small scale single cells up to stacks of several kW capacity. The evolution of material and fabrication strategies as well as the progress in terms of electrical performance are described and discussed. The data reported show that the MCFC technology has been successfully tested on stacks in the kW power class, however some problems still need to be solved to improve the stack performance. In particular, better control of the start-up phase, of electrolyte migration through the manifolds and of the gas feed distribution are required, based on the latest experimental data on a 50 cell stack with cell area 0.1 m(2) (cell active area 0.0702 m2), which operated for 780 h with a maximum performance of 4 kW at 206 mA/cm(2) at 50% fuel utilisation. Future development steps, which will lead to the realisation and operation of systems of several hundred kW, are presented.