Sixteen schizophrenics were studied both pre- and post-operatively by employing the Gardner Behavior Chart. All patients had been submitted to a prefontal lobotomy which closely followed the techniques of Freeman and Watts except that more extensive sections were made in the white matter so that the entire prefontal lobes were presumably functionally isolated. The Gardner Behavior Chart is essentially a 5-point rating scale in which the degrees of each behavior category are described in clear-cut objective terms. The categories covered are: (1) Attention to personal appearance, (2) Sleep, (3) Appetite, (4) Sociability, (5) Activity control, (6) Noise disturbance control, (7) Care of property, (8) Self-entertainment, (9) Cooperation in routine, (10) Work capacity, (11) Work initiative when alone, (12) Work initiative when closely supervised, (13) Willingness to follow directions. Individual improvement in behavior varied greatly following the operation. But, on the whole, patients became more cheerful and sociable than before, more observing and careful of their appearance and better able to control their behavior with relevance to the situation. In this group of chronic schizophrenics the difference between pre- and post-operative behavior as analyzed by the Gardner Behavior Chart was great enough to be statistically significant. In fact, a Gardner, index is of prognostic value for lobotomy patients, for the greater the difference between pre- and postoperative indices, the more satisfactory the ultimate social adjustment. Reliable post-operative readings can be obtained within twenty days. On the other hand, a prer-operative Gardner index of less than .75 suggests marked deterioration and contraindicates psychosurgical therapy in chronic schizophcenia.