According to J. L. Holland (1985, Making vocational choices: A theory of vocational personalities and work environments, Engelwood Cliffs, NJ: Prentice-Hall), there is a positive relationship between personality-environment congruence and satisfaction. The variable "group importance" was used in the present study as a mediator to explain why in some studies Holland's hypothesis was confirmed while in others no support was found. Group importance was measured by an inventory (reliability: .85) and by raters. Spearman rank order correlations between these measures of importance and congruence-satisfaction correlations were .68 (15 groups, p < .01) and .77 (23 groups, p < .01), respectively. Theoretical and practical implications of the findings are discussed.