As executives ascend in organizational structures, they become less likely to receive objective feedback from superiors, peers, and subordinates regarding the effects of their behavior within their organizations. This loss of feedback can contribute to perceptual blind spots within the executives. Such blind spots and their ensuing negative consequences have been found to be a major cause of executive derailment. Despite the enormous value of feedback, there is a paucity of proven methodologies for providing executives with constructive feedback on the effectiveness of their behavior. Consequently, the objective of this research was to design and validate an instrument that measures the perceived effectiveness of an executive's behavior, as judged by the executive's superiors, direct subordinates, and key peers. The instrument was constructed around a composite definition of executive effectiveness supported by a wide body of accepted theory and empirical studies. Face validity was established through the verification of the relevancy of the items to executive effectiveness. Reliability was established through the test-retest method. The instrument was evaluated for item clarity and clarity of directions by a pilot group of 10 executives from a San Diego manufacturing company. An experimental group of 50 executives from various business organizations participated in a line item face validity study. A second experimental group of 100 executives, including the 50 executives from the first experimental group, participated in a test-retest reliability study. The coefficient of stability was found to be statistically significant. The instrument's instructions, scoring, and administration procedures were standardized, in summary, a valid and reliable instrument for measuring perceived executive effectiveness was developed.