In the present work, a voltammetric study of permeability and redox behavior of diphenyl disulfide (Ph2S2) through a self-assembled monolayer of dioleoylphosphatidylcholine adsorbed on mercury is carried out; the results are compared with those obtained on a bare electrode; in this case, the reduction of Ph2S2 proceeds in a reversible way with the formation of a mercurial compound. The presence of the monolayer of phospholipid provokes an increase in the process irreversibility. Different mechanisms based on Ph2S2 adsorption either directly on a mercury drop or on phospholipids heads are proposed. The charge associated with the adsorbed Ph2S2 electroreduction was employed to calculate its solubility, and the method is compared with semiempirical expressions proposed in the literature for obtaining approximate values of solubility.