The purpose of this study was to develop and validate the Sexual Self-Efficacy Scale (SSES-E) for erectile disorder. The subjects consisted of 15 heterosexual couples with nonproblematic sexual functioning (normal group) and a sexually dysfunctional sample consisting of nine heterosexual couples and eight heterosexual single males (dysfunctional group). Most of the males in the dysfunctional sample were diagnosed as suffering from erectile disorder. Reliability of the SSES-E, based on test-retest and split-half correlations and on item analyses, appears to be reasonable. Validity, measured in three different ways, is also acceptably high. Suggestions for the use of this instrument in clinical practice and for future research are made.