Mild behavioral impairment (MBI) represents a recently introduced diagnostic concept that focuses on behavioral and personality changes occurring in late life and associated with cognitive decline. Nevertheless, the relationship between these dimensions remains unclear. This systematic review and meta-analysis aim to analyze the relationship between MBI and cognitive functioning. The review process was conducted according to the PRISMA-Statement. Restrictions were made, selecting the studies published in peer-review journals, including at least one cognitive measure and presenting the measurement of MBI. Studies that included participants with neurological disorders, dementia, or psychiatric disorders or that only did a neuroimaging or genetic study were excluded. Twenty-two studies were included in the systematic review, while in the meta-analysis seventeen studies featured data to be included in the analyses. The results were classified according to the following cognitive domains: global cognitive functioning, memory, language, attention executive functions, visuospatial skills, and processing speed. In the quantitative analysis, only global cognitive functioning, executive function, attention, and memory were evaluated. The results of both qualitative and quantitative analysis indicate that individuals with MBI exhibited diminished performance on cognitive tasks when compared to those without MBI symptoms. These results are stronger when evaluating the various domains individually (particularly memory and executive functions) than when a global assessment was made. These findings highlight the potential role of MBI symptoms as early indicators of neurodegenerative processes, reinforcing the necessity for comprehensive assessments that encompass both behavioral and cognitive evaluations. The early detection of these symptoms in prodromal phases can be very useful for the development of non-pharmacological interventions and may provide relevant guidelines for clinicians in the management and diagnosis of neurodegenerative disorders.