Lead selenide is a narrow-gap semiconductor material. It finds applications in infrared emitting and detecting devices, with a performance closely related to surface properties. Charge-carrier recombination at the surface can be reduced by passivation, for instance by formation of a native oxide by anodic oxidation. in this work, the anodic behavior of single-crystal lead selenide in aqueous solutions at pH 10 is studied under potentiostatic conditions. Surface analysis using a scanning electron microscope and energy dispersive X-ray spectroscopy was pet-formed. A ternary oxide was characterized as the oxidation product. Two different growth mechanisms were found : an "island growth" (two-dimensional nucleus growth) and the growth of a homogeneous film following the high-field model. The process of oxidation depends significantly on the pretreatment of the lead selenide surface. The electronic properties of the oxidation laver were investigated with photocurrent measurements, resulting in a bandgap of the anodic oxide of 1.6 eV. From I-V curves a specific conductivity was determined in the order of 10(-9) Omega(-1) cm(-1) for the oxide film.