  We give a brief overview of 20 open theoretical questions in supersymmetric
particle physics. The 20 questions we have chosen range from the GeV scale to
the Planck scale, and include issues pertaining to the Minimal Supersymmetric
Standard Model and its extensions, SUSY-breaking, cosmology, grand unified
theories, and string theory. Throughout, our goal is to address those topics in
which supersymmetry plays a fundamental role, and which are areas of active
research in the field. This survey is written at an introductory level and is
aimed at people who are not necessarily experts in the field.
  (To appear as an Overview Chapter in the review volume "Perspectives on
Supersymmetry", edited by G. Kane, to be published by World Scientific.)
