Purpose: This study aimed to explore how public primary healthcare workers in a medically underserved area perceive the four core attributes of primary care-comprehensiveness, accessibility, continuity, and coordination. Methods: A qualitative descriptive design was applied. A total of 37 public health and nursing officers and related personnel working at a public health center, public health subcenters, and primary health posts in a rural underserved area of Gangwon State, Republic of Korea, participated in the study. Data were collected from November 20 to 27, 2025, using a pre-structured open-ended survey based on Starfield's framework, supplemented by follow-up interviews with four participants. Data were analyzed using directed content analysis with the four attributes as a priori categories. Results: For comprehensiveness, chronic disease management (45.9%) was most frequently identified, while gaps were noted in mental health, child welfare, and integrated services (32.4%). For accessibility, transportation and geographic barriers were the most prominent (81.1%), and 70.3% of participants were favorably toward remote monitoring, contingent on support for older adults with limited digital literacy. For continuity, frequent staff turnover threatened relational continuity, highlighting needs for accumulated data systems and multidisciplinary management. For coordination, intra-public-health linkages functioned well, whereas linkages with hospitals and welfare agencies were limited due to the absence of integrated platforms and a designated coordinator (32.4%). Nurses emphasized clinical management and digital hub functions, whereas non-nursing personnel emphasized lifestyle interventions and face-to-face coordination. Conclusion: Strengthening multidisciplinary integrated service planning, digital and mobile accessibility, workforce stabilization with integrated information platforms, and coordinator-centered structures is essential. Coordination competency should be a required component of capacity-building programs for primary care nurses. In particular, primary care nurses are well positioned to serve as care coordinators bridging clinical management, digital monitoring, and inter-agency linkage in medically underserved areas, and nursing curricula and continuing education should reflect this expanded role.