Simulation based medical training requires real time interactivity. While real time graphical display requires an update rate of 30 Hz, real time force feedback requires a much higher update rate of 1 kHz. The demand for extreme computational efficiency delimits the complexity of the computational models that can be used for simulation. In this paper we develop two specializations of a meshfree technique, the point collocation-based method of finite spheres (PCMFS), for real time simulation of soft tissues during minimally invasive surgery (MIS). Simulations using realistic three-dimensional geometries are presented and are compared with solutions using more traditional finite element methods in terms of speed and accuracy. The integration of the proposed schemes into a practical surgical simulation system is also discussed. (c) 2005 Elsevier Ltd. All rights reserved.