This study tested sex stereotyping of occupational roles as a determinant of source credibility. The two main independent variables involved sex of communicator and occupation of communicator. Occupations, analyzed only in terms of whether or not the occupation could be considered typically a "man's" or a "woman's" field, were chosen on the basis of a pretest used to determine male or female dominance. The dependent variables were initial source credibility scores as measured by a semantic differential. Independent variables were manipulated through an introductory statement. For each occupation all information was held constant. Subjects were then asked to rate each proposed speaker on the basis of information given. The authors used a semantic differential consisting of 12 scales. Results from the study indicate that sex of the source alone (sex stereotypification) does not account for credibility ratings and that sex stereotyping of occupational roles cannot be considered a single determinant of source credibility. Tables of findings are included. (Author/JM)