We performed nine studies with partly overlapping samples from the United States and Germany to establish the reliability, validity, and usefulness of the concept of action style-a person-specific approach to action. Two principal-components-analyses factors are dealt with in more detail: goal orientation and planfulness. Both show high consistencies and have test-retest correlations of r = .47 and .48, respectively, across 8 months. In one validity study, the correlations between self-ratings and peer ratings are .36 for goal orientation and .54 for planfulness. In a second validity study, a quasi experiment, with thinking-aloud protocols on planning a day in a strange city, showed rather weak correlations between raters and subjects, but these correlations improved when we included only those subjects who were easy to observe. A third validity study on the correlations with impulsivity showed that goal orientation is little related but that planfulness is to a higher degree. There are small but consistent and significant relations with depression and with coronary-prone Type A behavior, and there are correlations with work-related constructs of stress and resources at work as well as with performance in college. © 1987 American Psychological Association.