This evaluation of Herzberg's theory of motivation discusses its ambiguities and the influence of the tendency for people to give “socially desirable” answers. Evidence from the authors' experiments suggests that the theory is untenable as a description of the structure of job attitudes and the determinants of job satisfaction and dissatisfaction. The authors acknowledge that a policy of job enrichment derived from the application of the theory would be likely to promote satisfaction and allay dissatisfaction. A concise summary of their analysis and conclusions is given at the end of the article.