Abstract BACKGROUND Long-term cognitive sequelae of paediatric brain tumors are of increasing interest. The role of histology and surgery remains still unclear. Our study aimed to evaluate children cognitive functioning before and after brain tumors surgery, and at the end of additional treatments. METHODS New diagnoses of paediatric primary brain tumors were prospectively assessed. Neurocognitive evaluations were performed at diagnosis (T0), within 7-10 days from surgery (T1) and 12-18 months after the end of treatments (T2). Language, learning and memory, attention, executive functions, visuo-constructional and sensorimotor skills were evaluated at T0 and T1, Intelligent Quotient (IQ) was explored at T0 and T2. RESULTS Twenty-five patients (M:F=15:10, mean age 10.9±3.4 years) were enrolled between January 2019 and December 2022. In comparison to normal values (>7.0), at baseline patients showed major deficits in narrative memory (6.6±3.7, p<0.001) and visuo-spatial memory (copy design tasks: general 6.8±3.9, p<0.001, specific 6.2±3.3, p<0.001, motor 5.2±3.2, p<0.001). At T1 assessment, significant deficits remained in narrative memory (6.2±3.3, p<0.001) and visual-motor coordination (copy design tasks: specific 5.9±3.0, p<0.001 and motor 4.8±4.3 p<0.001); attention and visual-constructional abilities significantly improved (p=0.04 and p=0.001). On the visual construction test, children with high-grade histology scored lower than the low-grade group (Rey- Osterrieth complex figure-copy 5.1±4.4 vs 11.0±4.3; p=0.019). At T2 evaluation children showed persistent deficits in visuo-spatial processing and a possible decline in IQ scores, with lower scores compared with T0 (93 vs 100, p=0.05). CONCLUSIONS Children with brain tumors may present several neuropsychological impairments at diagnosis, particularly those with high-grade diseases. Surgery may have a positive effect on the recovery of some cognitive functions. However, cognitive decline may worsen over time. Baseline and periodic neurocognitive evaluations should be encouraged to identify functional difficulties and to develop a tailored treatment approach for the patient.