SUMMARY Background. Executive dysfunction is known to be a common sequela of injury to the frontal lobes. However, clinical experience suggests that execu- tive dysfunction may also accompany injury to the temporal and parietal lobes. In addition to focal symptoms, behavioral disorders are often observed in patients after severe traumatic brain injury (TBI), regardless of localization. Material and methods. Forty patients recovering from very severe TBI were examined, including twenty with frontal lobe injuries and 20 with tem- poral and/or parietal injuries; the groups were matched for age and sex. Apart from the analysis of documentation, the clinical interview and the psycholog- ical interview, the patients were also examined with the Clinical Test of Executive Functions – Revised (CTEF-R) and with the Mini-Mental State Examination (MMSE). Results. Executive dysfunction appeared in almost all these patients regardless of the location of the brain damage. Nevertheless, the degree of dysfunction was considerably higher in patients with frontal lobe damage. No essential correlations were found between the level of overall cognitive func- tioning measure by the MMSE and the level of executive dysfunction. Conclusions. Executive dysfunction is not the result of frontal damage alone, but frontal damage is a predictor of its severity. Microgenetic theory can be used to explain best the results we obtained. TRAUMATIC INJURY TO THE FRONTAL AND TEMPORAL-PARIETAL LOBES OF THE BRAIN AND EXECUTIVE DYSFUNCTION Bożena Grochmal-Bach 1 , Beata Lukaszewska 2 , Katarzyna Guzińska 2 , Henryk Olszewski 2 , Waldemar Tlokiński 3 , Anna Pufal 4 , Dominika Sadowska 4 1 Institute of Applied Psychology, Jagiellonian University, Cracow, Poland 2 Institute of Psychology, Gdańsk University, Gdańsk, Poland 3 Ateneum College, Gdansk, and Department of Cognitive Sciences and Communication, Gdańsk University, Gdańsk, Poland 4 Center for Cognition and Communication, New York, NY. USA Key words: traumatic brain injuries, executive functions, microgenetic theory 202 ORIGINAL ARTICLE ACTA ACTA Vol. 5, No. 4, 2007, 202-212 NEUROPSYCHOLOGICA NEUROPSYCHOLOGICA