Mindful parenting is the extension of intra-personal mindfulness to inter-personal processes by developing and fostering mindfulness during interactions with a child when acting in the role of a parent. While some empirical evidence points to various benefits of mindful parenting both for the parent and the child, suitable measurement tools for mindful parenting are still being developed, especially for use in non-Western countries such as Korea. The present study involved development of a Korean version of the Interpersonal Mindfulness in Parenting (IM-P) scale using a large sample of Korean parents (n = 554) recruited online and a second, replication sample of Korean parents with children attending kindergarten (n = 283). Using an iterative approach of exploratory and confirmatory factor analysis guided by conceptual criteria, an 18-item Korean version of the instrument (IM-P-K) met psychometric criteria of classical test theory. Rasch analysis confirmed internal validity of this solution and also produced algorithms to convert the total ordinal-level summary scores to interval-level data. While the reliability of the six individual three-item subscales was only marginally acceptable, the reliability of the total interval-transformed score was excellent. The IM-P-K total scores correlated in expected directions with various other psychological constructs known to be associated with mindfulness, such as self-compassion, depression, psychological well-being, and perceived stress. This 18-item IM-P-K thus offers a suitable self-report instrument to investigate mindful parenting in Korean samples.