Vibrations in robot action, both in the arm control system and arm itself, and in the transported load, are a serious problem in the development of high speed systems. The paper discusses the typical causes of vibration resulting from the motion command in path controlled robots and those due to the failure of a system to meet the specified command through power and performance limitations. Experimental results illustrating such phenomena are presented. Methods of reducing the magnitude or occurrence of such vibrations through the improved design of motion commands, which take account of the vibratory nature of the system and load, are presented.