Rapid scan cyclic voltammetry has been employed to probe the potential induced transitions of a dioleoylphosphatidylcholine (diOPC) monolayer deposited onto a mercury surface. By employing two different types of electrodes, a hanging mercury drop electrode (HMDE) and a mercury-film-coated gold electrode (J-electrode), we were able to deposit the diOPC monolayer in tails-down and heads-down fashion, respectively. Comparison of the results for these two deposition methods suggests that the tails-down structure is the more stable one at potentials of up to -0.80 V. Cycling of the potential to about -1.20 V for the electrode with the monolayer deposited in a heads-down fashion results in a complete reorientation of the monolayer to a tails-down configuration. We have studied this process in the presence of halides and find that whereas the onset of this process is independent of the halide, the rate depends strongly on the identity of the halide. We have, in addition, studied the pH and temperature dependencies of this transition. Finally, we propose a tentative mechanism for this transition.