Abstract. This paper analyses the technological capabilities of a novel rotary (EDM) electrical discharge machining process for the manufacturing of high aspect ratio cylindrical micro-components. The process is called Inverse Electrical Discharge Grinding (ISEDM). An experimental analysis has been carried out on high speed steel (tool steel Vanadis 23), using a conventional EDM machine and graphite electrode. The effect of pulse off-time, work piece final diameter and machining length on material removal rate, electrode wear ratio, radial accuracy and surface roughness has been quantified. From the study, optimum strategies that involve the use of different EDM regimes for achieving the optimum requirements can be defined. Micro-pins of 0.3 mm diameter with aspect ratio as high as 100:1 have been successfully manufactured.