A major issue in marketing concerns potential bias from nonreturns in survey research. This study was designed to examine if their are personality characteristics that differentiate the respondents from nonrespondents in a mailed questionnaire. Five hundred and eight salesmen of a national marketing firm participated in the study. Nine of the twenty variables studied had a significant difference between respondents and nonrespondents. Practical and theoretical considerations suggests that a respondent population may be an even more select group than previously considered.