Background: Central nervous system (CNS) infections in patients with neoplasia have high morbidity and mortality. This study aims to describe the demographic, clinical, and microbiological characteristics of this population group at the Instituto Nacional de Cancerologia (Bogotá, Colombia).Methods: A descriptive, cross-sectional, and retrospective study in Colombia’s largest public cancer center between 2010 and 2020. Patients of all ages with confirmed diagnoses of solid-organ tumor or hematologic malignancy and cerebrospinal fluid positive for a specific microorganism were included. Patients with insufficient information or who were HIV positive were excluded. Data consolidation was done in RedCap, and statistical analysis was performed using STAT 16.Findings: Included 82 patients, with a mean age of 37 years [IQR 30-39] and male predominance (67.1%), with hemato-lymphoid (29.3%) or solid-organ (70.7%) neoplasms. Of the patients, 59.8% underwent neurosurgical management, 57.3% chemotherapy, and 35.5% radiotherapy. The most frequent clinical syndrome was meningitis (57.3%); 84.2% were diagnosed by culture, with Staphylococcus and Enterobacteriaceae being the most frequent germs. Viral, fungal, and parasitic infections were also detected. 98.7% were treated; mortality occurred in 41.5%.Interpretation: This is the first study in Latin America that evaluates CNS infections in patients with neoplasia, and the second to include only infections with confirmed germs and analysis by subgroups. The neoplasm type and causative germs differ from what is reported in the literature. We obtained a higher mortality and a higher percentage of sequelae than what had been documented in previous studies.Funding: Universidad Nacional de Colombia and Instituto Nacional de Cancerología, Bogotá, Colombia.Declaration of Interest: None.Ethical Approval: This project is in line with international standards, such as the Declaration of Helsinki, the Nuremberg Code, the Belmont Report, and the guidelines established by the Council for International Organizations of Medical Sciences (CIOMS). The study was conducted in accordance with good clinical practice (GCP) standards. The ethical risk level of the study according to Article 11 of Resolution No. 008430 of 1993 issued by the Ministry of Health of Colombia is “Research with minimal risk.” To guarantee the confidentiality of patients included in the research, the variables related to their identity were eliminated (Statutory Law 1581 of 2012 and Decree 1377 of 2013). The protocol was submitted for review and approval by the Ethics Committee of the Universidad Nacional de Colombia and INC.