This study examines Chungnam dialect speakers’ perceptual dialect boundaries, their images of Korean dialects, and also their auditory ability to distinguish the dialects. Thirty Chungnam residents participated in this research as subjects and performed four tasks: pile-sorting, description of dialect images, dialect recognition, and a short interview. The focus of the study was to examine the informants’ subjective dialect boundaries among Chungnam dialect and geographically adjacent Chungbuk, and Jeonbuk dialects, the informants’ images about these dialects, and their ability to distinguish the three. The results from the tasks suggest that speakers of Chungnam dialect perceive Jeonbuk dialect at least as close as or even closer than Chungbuk dialect. The results from the dialect recognition experiment also reveal auditory-perceptual similarity between Chungnam and Jeonbuk dialects. Chungnam dialect speakers were, in addition, analyzed as having relatively favorable images about their dialect.