Object The aim in this study was to assess the state and trait types of anxiety as well as current depression before and after surgery in patients affected by brain tumors. The relationships between these affective disorders and the patient's sex, tumor histology, and laterality of the tumor were also evaluated. Methods A total of 72 patients affected by a primary brain tumor were enrolled in the study. Histological grades were assigned according to the World Health Organization classification. State and trait anxiety were assessed using the State and Trait Anxiety Inventory; current depression was assessed using the Zung Self-Rating Depression Scale. Cognitive impairment was assessed using the 10-item Short Portable Mental Status Questionnaire. Psychometric evaluation was assessed before surgery and at 1, 3, 6, and 12 months after surgery. Results Before brain surgery, 62.5% of patients showed state anxiety, 50% of patients showed trait anxiety, and 9.7% of patients showed current depression. During the follow-up period there was no significant variation in the percentage of patients with state anxiety (p = 0.416) and trait anxiety (p = 0.7), whereas a significant increase in the percentage of those with current depression was found (p < 0.0001), in particular at 1 month (p = 0.002) and 3 months (p = 0.039) after surgical treatment. The tumor's laterality and histology showed no correlation with psychometric variables, whereas a relationship between the presence of trait anxiety at the enrollment and current depression after surgery (p < 0.0001) was found. Conclusions Patients affected by brain tumors frequently experience affective disorders. After brain surgery, a depressive state can develop. The psychometric assessment could be useful in these patients for quick recognition of psychological disorders.