Introduction: An emerging perspective of dyadic coping with chronic illness argues that concordance in the appraisal of illness is crucial for collaborative attempts at seeking information, making treatment decisions, and planning for long-term management of the illness and psychological and physical adjustments of both the care provider and care recipient. The present study examined whether persons with mild cognitive impairment (PwMCIs) and their family care partners (CPs) exhibited concordance in their awareness of deficits in the PwMCIs. Furthermore, this study explored the differences in concordance based on the relationship of the informant to the PwMCI, specifically spouse CP (SCP) versus adult child CP (ACCP). Method: PwMCI-SCP pairs (n = 55) and PwMCI-ACCP (n = 14) pairs provided reports on their awareness of PwMCI’s functional and cognitive deficits. CPs also reported their knowledge about dementia. Results: SCPs, but not ACCPs, reported greater deficits in everyday activity than PwMCIs’ self-reports. Additionally, compared to SCPs, ACCPs had more accurate knowledge about dementia, and their perception of PwMCI deficits corresponded more closely to PwMCI’s self-perception. Discussion: These findings demonstrate that concordance in awareness of PwMCI deficits varies across functional and cognitive areas and types of dyads. The results also highlight the importance of mild cognitive impairment-related education and support programs for care dyads to strengthen concordance, which is likely an important underpinning for effective coping as the illness progresses.