Persons with psychotic disorders receive devalued labels. Despite considerable theorizing, the proposition that these labels affect the course of psychotic illness has rarely been subjected to investigation. The lack of an adequate operational measure for the labeling construct has hampered research. The present report describes the development of the Social Response Questionnaire (SRQ), a measure of the 'sick' label which incorporates moralistic attitudes, fear of dangerousness and negative expectations attached to the role of the severely psychiatrically ill. This 32-item scale, a multidimensional measure of informal labeling, which may be administered in a self-report format or to significant others, permits the study of dose-response relationships. The SRQ is internally stable. It also exhibits construct validity. Schizophrenics and persons with affective psychosis label themselves and are labeled by others more harshly than persons with Crohn's disease or normals. While self-percepts and the perceptions of significant others are fairly congruent for normals and persons with a significant physical illness, there is no agreement between the self-ratings of psychotics and their significant others. Psychotic persons view themselves more negatively than Crohn's disease sufferers or normals, but not as negatively as their therapists, families and friends. Potential uses for the SRQ in longitudinal research are addressed.