Ego development and multiple self-images were studied in nonpsychotic psychiatric patients, diabetic patients, and healthy high school students. The results reported are drawn from the first year of a four-year longitudinal project investigating the psychosocial development and family interactions of impaired and at-risk adolescents. Both groups of patients, especially the psychiatric group, were significantly lower in their ego development and showed less self-image complexity than the high school students. These findings are discussed both in terms of understanding developmental deviation in these two chronically ill groups, and as a strategy for investigating formulations being proposed in the new selfpsychology framework.