Our objective was to explore the impact of the histopathological tumor type on affective symptoms before surgery among male and female patients with supratentorial primary brain tumors. A total of 44 adult patients were included in the study. Depression and anxiety were measured using the Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory. Additionally, clinical interviews, including the Hamilton Depression Rating Scale (HDRS), were conducted. The general function of patients was measured with the Karnofsky Performance Status scale (KPS). All measures were obtained before surgery and therefore before the final histopathological diagnosis. All self-rating questionnaires but not the HDRS, showed significantly higher scores in female patients. The functional status assessed with the KPS was lower in female patients and correlated to the somatic part of the BDI. We further found a tendency for higher HDRS scores in male patients with a WHO grade 4 tumor stage compared to female patients. This finding was supported by positive correlations between HDRS scores and WHO grade in male and negative correlations between HDRS scores and WHO grade in female patients. In conclusion the preoperative evaluation of affective symptoms with self-rating questionnaires in patients with brain tumors may be invalidated by the patient's functional status. Depression should be explored with clinical interviews in these patients. Sex differences of affective symptoms in this patient group may also be related to the malignancy of the tumor, but further studies are needed to disentangle this relationship.