Objectives: Cognitive abilities might be impaired due to brain lesions in children and adolescents. This study aimed to investigate neuropsychiatric indicators in children and adolescents with primary brain tumors and other brain space-occupying lesions (SOLs) before and after the surgical procedure. Materials & Methods: The current pre-post study was conducted on 81 patients with brain SOLs aged under 18 years hospitalized in the Neurosurgery Ward of Imam Reza university hospital, Tabriz, Iran, within 20 December 2016 to 20 December 2017. The patients with metastatic brain tumors were excluded. Before and after the surgical procedure, Digit Span forward and backward task (to assess working memory), Stroop Task and Trail Making Task A and B (to assess attention), and Rey-Osterrieth Complex Figure Test (ROCF) (to assess visuospatial memory) were carried out. Then, the scores of the tests were compared to standard values and postsurgical scores. Results: The most prevalent type of brain SOLs was medulloblastoma, and the most prevalent region of involvement was the posterior fossa. The scores of all tests after the surgery were significantly improved, compared to those before the surgery (P<0.05). In the assessment of Digit Span forward and backward task scores, there was no significant difference between the scores of patients before the surgery and standard values (P>0.05). Regarding the scores of various stages of the ROCF, the scores of the immediate recall stage were significantly low (P<0.05). Regarding Trail Making Task A and B and Stroop Task before the surgery, only Trail Making Task A and B scores were significantly increased (P<0.05). The scores of Trail Making Task A were significantly higher in patients with medulloblastoma and anatomically in left temporal tumors, which indicated greater damage to the attention field (P<0.05). In addition, in cerebellar tumors, the scores of the immediate recall stage of the ROCF were significantly lower than in other brain tumors or SOLs (P<0.05). Conclusion: The visuospatial memory and attention of preoperative assessments were significantly impaired, compared to those of the healthy population (P<0.05). Working memory, visuospatial memory, and attention showed improvement, compared to those before the surgery. Deficits in the attention domain were greater in medulloblastoma.