Sentence completion responses of a sample of 240 adult males, ages 35-80 yrs, were scored for the J. Loevinger et al (1970) ego development levels. Correlation of these scores with a series of objective personality trait measures collected over a 9-mo period showed no relation between ego level and measures of neuroticism or extraversion. However, as hypothesized, ego level was significantly related to 7 of 10 measures of openness to experience. Blind judgments of protocols from the upper and lower 20% of the Experience Inventory total distribution demonstrated that openness is expressed in sentence completion responses, and examples of characteristically open and closed responses are given.