The Workshop on Ambipolar Potential Formation and Control in Bumpy Tori and Mirrors was held at Oak Ridge, Tennessee, May 11–12, 1981. Attending were approximately 100 scientists from both the USA and Japan.The purposes of the workshop were (1) to evaluate the current status of experimental and theoretical understanding of the role played by the ambipolar potentials and (2) to identify processes that influence the formation and control of the ambipolar potentials.