Introduction: The decline of cognitive functions is one of the main negative changes associated with aging. In recent years, interest has grown in determining whether inflammation affects cognitive decline and to what extent. The objective was to review the literature for studies that investigated the association between inflammation and performance in specific cognitive domains (example, memory, attention, or language), and in adults of all ages. Methods: The PubMed database was consulted between 2017-2022. A systematic review was carried out according to the PRISMA statement and 27 scientific articles were selected. Results: 26 out of 27 articles warned that greater inflammation is associated with poorer performance in attention, memory, executive functions, language, and processing speed, among the main cognitive domains. The evidence includes adults of various ages with and without a history of inflammatory or neuropsychiatric disease. Eight longitudinal studies indicated that inflammation is an important predictor of cognitive decline. Conclusion: The reviewed studies suggest that a higher level of inflammation is associated with worse performance in specific cognitive domains, with evidence for adults of different ages, with and without a history of disease. Some methodological recommendations are offered to improve the comparability between studies.