Communication between cancer patients and caregivers is often suboptimal. The Cancer Communication Assessment Tool for Patient and Families (CCAT-PF) is a unique tool developed to measure congruence in patient-family caregiver communication employing a dyadic approach. We aimed to examine the cross-cultural applicability of the CCAT in the Korean healthcare setting. Linguistic validation of the CCAT-PF was performed through a standard forward-backward translation process. Psychometric validation was performed with 990 patient-caregiver dyads recruited from 10 cancer centers. Mean scores of CCAT-P and CCAT-F were similar at 44.8 for both scales. Mean CCAT-PF score was 23.7 (8.66). Concordance of each items between patients and caregivers was low (weighted kappa values <0.20 for all items and Spearman's rho <0.18 for scale scores). Scale scores did not differ significantly across a variety of cancer types and stages. The CCAT-P or CCAT-F score was weakly associated with mental health and quality of life outcomes. The CCAT-PF was correlated weakly with both patient-perceived and caregiver-perceived family avoidance of cancer care scales. The CCAT-PF Korean version showed similar psychometric properties to the original English version in the assessment of communication congruence between cancer patient and family caregivers.