In older adults, physical frailty and cognitive impairment contribute to adverse outcomes. However, the research on mechanisms underlying physical frailty and cognitive impairment is limited. Low-grade chronic inflammation is a characteristic of aging. Particularly, an imbalance in pro- and anti-inflammatory mechanisms may be involved in frailty and neurodegenerative disorders. Therefore, exploring the inflammatory markers of physical frailty and cognitive impairment is crucial to fully understanding these mechanisms and establishing a substantial link between these two disorders. Notably, few studies have focused on exploring inflammatory markers in both physical frailty and cognitive impairment, posing a major challenge in elucidating the link between them. Therefore, substantial efforts are required for the better prevention of physical frailty and cognitive impairment. In this review, we explored the role of inflammatory markers as a potential link between frailty and cognitive impairment.