6088 Background: In a worldwide first study on the topic (see Abst. ASCO, 2003) a questionnaire (A-ACT-Q) for the measurement of the underlying dimensions of physicians' attitudes towards alternative cancer therapy (ACT) was devised. This study validates the results and quality of the A-ACT-Q in a sample of 320 medical students. Methods: Apart from the A-ACT-Q the entire inventory contained several personality questionnaires (NEO-FFI, Help- and Hopelessness and Rationality/Emotional defense). Results: Factor analysis of the A-ACT-Q yielded four underlying dimensions of attitudes towards ACT, all featuring high reliability indices: 1. Openness (α=.89), (Knowledge, α=.84; Application (α=.79); 2. Rigidity (α=.92) (Internal-, α=.89; and External, α=.81); 3. Economic Efficiancy (α=.78), 4. Desperation (α=.86). Further analyses (MANOVA, regression analyses) showed anxious undergraduates in opposition to students near at the graduate (graduanti) to regard ACT as equal, yet cheaper means of therapy. Graduanti with high rationality believe ACT to be money-grubbing and a waste of time. Graduanti with high anxiety-scores, however, show much interest in ACT-training, whereas students with high levels of hopelessness seek out ACT, in order to acquiesce to patients' wishes. Students with low levels of hopelessness, on the other hand, have faith in traditional medicine, as do students with low anxiety- and at the same time high extroversion-scores. Conclusions: The dimensions of the A-ACT-Q could be replicated and are shown to be reliable and valid. These results concur with those of the preliminary study done on physicians and show attitudes towards ACT to be dependent on personality and professional socialisation. This would suggest decisions on the implementation of therapy not being made on the ground of empirical fact, but rather being the result of predispositioned personality variables. No significant financial relationships to disclose.