In two previous sntdies (2, 3) it was found that frustration impaired the WISC coding performance of both a group of middle-class Jewish boys and a group of institutionalized children with conduct disorders. In a further effort to determine the generality of these findings as well as investigate the reactions to frustration of children who are assumed to have difficulty tolerating stress, the present snidy utilized a group of brain-injured children. Thirty-six boys (MI,,, = 9.22), suffering from various degrees of cerebral damage and receiving remedial work in such areas as reading and mocor skills, comprised the sample. After taking the WISC coding subtest, Ss were randomly assigned in equal numbers to a high-, a low-, or a no-frustration group. The procedure used to produce frustration is fully described elsewhere ( 3 ). Basically, Ss in the highfrustration group were interrupted just prior to completing a marble board and therefore could not win a prize. Low-frustration Ss were interrupted at the marble game, but no goal (prize) was specified for them. Ss in the no-frustration group were never exposed to the marble game. Following the treatments, each S received a revised form of the coding subtest. The results of a simple analysis of variance of difference scores on the coding subtest for pre- and post-frustration experience indicated a significant main effect of frustration (F = 3.41, p < .O5). A series of t tests revealed that there was significantly greater impairment of coding performance in the high-frustration than in either the low-frustration or no-frustration groups. Furthermore, a comparison of pre- and post-Frustration errors indicated that the high-frustration group made significantly more errors following the experimental treatment than did either of the other two groups. It seems clear then that the experimentally produced frustration consistently affects WISC coding performance within a fairly hecerogeneo~~s sample of children. Additional criterion measures will be investigated in subsequent research.