Conventional laparoscopic surgical tools penetrate a patient body through a fixed point called trocar point. Surgeons maintain this pivoting point on the patient body with their coordinated hand movements. Mechanism used for achieving this kinematic constraint is known as Remote Centre of Motion (RCM) mechanism and is widely used in surgical robots. Active RCM mechanism will enable positioning the constraint point virtually anywhere within the reach of the linkage. In this work, we present an optimisation strategy for an active RCM to minimise the extracorporeal workspace. The link lengths of the active RCM mechanism have been optimised and the dexterity of the tool has been analysed for various trocar positions. Kinematic analysis of the RCM mechanism, optimisation strategy, and the results of the dexterity analysis are presented. © 2013 ACM.