The present study investigates identity disorders in schizophrenics and borderlines. Nineteen schizophrenics and 17 borderlines were compared with 18 normal controls. The technique used was an adapted version of the repertory grid test to describe the self and nine significant others (i.e., family members). Three indices were derived from the 10 person x 20 self-generated-attribute matrix to measure the extent to which self was differentiated from others: (1) overlap of salient attributes, (2) overlap of opposite attributes, and (3) degree of differentiation among others. Results showed that both schizophrenics and borderlines describe themselves more in terms of opposites than in terms of salient attributes. Differentiation among significant others was severely impaired in schizophrenics and preserved in borderlines. These findings were interpreted as a failure of the individuation process in schizophrenics and as an incomplete construal of self-identity in borderlines.