Object: Aim of the present study was the identification of the neural basis of cognitive strategic behaviour. Moreover, theories about the functional and hierarchical organization of cognitive functions within the prefrontal cortex (PFC), about the differentiation between subcomponents of strategic abilities as well as about the integration of functional imaging and neuropsychological studies in cognitive neuroscience were to be examined. Method: Functional Magnet-Resonance-Imaging (fMRI) was used for examining the neural basis of strategic behaviour. In two follow-up studies, different aspects of strategic functions were studied in patients with Parkinson’s Disease respectively tumours within the prefrontal cortex. Experimental paradigms were spatial and verbal working memory as well as Numerosity Judgement tasks. Results: fMRI showed increased activation in dorsolateral prefrontal cortex, cerebellum and hippocampus in strategic versus unstrategic trials, whereas the latter caused stronger activations in areas associated with maintenance in working memory. Evidence for a rostrocaudal hierarchical organization of cognitive functions within the human prefrontal cortex could be supplied as well as for a hybrid organization concerning different processes and domains. Moreover, both patient groups showed deficits in cognitive and metacognitive strategic functions. Conclusions: The dorsolateral PFC plays a crucial role for human cognitive strategic behaviour. Even simple strategies can cause significant relief of memory load. This is accomplished through additional activation of hierarchically superior brain regions. Patients with lesions of the frontal lobes exhibit deficits in strategic functions, which leads to important implications for neuropsychological diagnostic and therapy.