The general properties of the Cooper minimum in molecules are reviewed. Experimental results from synchrotron radiation together with theoretical calculations are presented on both the partial cross sections and angular distribution parameters, β. A detailed examination of HCl is used as an example. Previously unpublished results on CCl n H4- n , CCl n F4- n , ethylene dichloride, I2 and ICl are included. The Cooper minimum is largely discussed as a perturbation from atomic behavior, and is examined as a function of atomic number. The Cooper minimum is also examined as a function of chemical environment. Finally, needs for future research are briefly described.