Earlier work. based upon ex situ surface analytical measurements. found that a disordered Pd(111) surface can be spontaneously reordered upon exposure, at ambient conditions, to a dilute aqueous solution of iodide. This phenomenon has been re-examined by in situ atom-resolved scanning tunneling microscopy. The results from the present study, while corroborating the chemisorption-induced disorder-to-order surface reconstruction observed earlier. indicate that the kinetics of the structural rearrangements may not be as rapid as initially thought.