Recent investigations in robot mechanics at Dipartimento di Ingegneria Meccanica per l’Energetica of the University of Naples Federico II (D.I.M.E.) are here reported. In general, the aim of these investigations is to obtain trajectories and paths from the end effector of a robot with the highest possible accuracy. In particular, these investigations consider the influence of circumferential backlash and transmission elasticity on the accuracy of a trajectory, and the possibility of obtaining more accurate paths via optimum positioning and orientation of the paths in the work space. The investigations were carried out both through simulation and experimentally; the simulations were performed using the ADAMS and Matlab-Simulink computer programs while the experiments involved use of an industrial robot and a prototype designed and built at D.I.M.E. ©1999 American Institute of Physics.