By means of the phase transfer method, bovine serum albumin (BSA) was solubilized into a reverse micellar phase comprised of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and isooctane. Of particular interest in this work are the effects of PH and the added salt type and its concentration on the solubilization efficiency. When a salt such as KCl, NaCl, MgCl₂, or CaCl₂ was added to the aqueous phase at a concentration of 0.1 M, maximum solubilization efficiency was attained at values of PH ranging from 5 to 7 depending on the added salt type. For NaCl and CaCl₂, increasing the salt concentration up to 1 M resulted in increases in the solublization efficiency, but the addition of MgCl₂ beyond 0.1 M showed an anomalous trend. Further, it is noteworthy that, to a large extent, the protein precipitated at the interface between the organic and aqueous phases at lower PH and lower salt concentrations. The size of the water pool of the reverse micelle was estimated by measuring the molar ratio W_o of water to the surfactant. Independent of the PH in the aqueous phase, the value of W_o for MgCl₂ almost remained constant at 20. In contrast, increasing the salt concentration led to decreases in the value of W_o for KCl and CaCl₂.