This ethnobotanical study documents medicinal plant diversity and traditional healing practices in Barguna District, a coastal region of Bangladesh. Twenty-seven traditional healers (kabiraj) were interviewed using semi-structured questionnaires during April-June 2025. A total of 68 medicinal plant species representing 34 botanical families were documented. Fabaceae emerged as the most represented family (10.3%), followed by Lamiaceae (8.8%). Trees constituted the dominant growth form (35.3%), with leaves being the most frequently utilized plant part (32.4%). The documented species treat twelve major ailment categories, with gastrointestinal disorders (22.8%) being most prevalent. Informant Consensus Factor (FIC) values ranged from 0.62 to 0.89, with gastrointestinal disorders showing highest consensus (FIC = 0.89), followed by respiratory ailments (FIC = 0.85) and diabetes (FIC = 0.82). Citation Frequency (Cf) analysis revealed Azadirachta indica (Cf = 0.89), Ocimum sanctum (Cf = 0.81), and Curcuma longa (Cf = 0.78) as culturally most significant species. Decoction (34.6%) and paste application (23.4%) were predominant preparation methods, with oral administration (61.2%) being most common. The demographic profile indicated that 81.5% of healers acquired knowledge through family inheritance, highlighting intergenerational transmission patterns. However, this traditional knowledge faces erosion threats from modernization, with 44.4% of practitioners lacking formal education and 18.5% aged above 60 years. The study reveals substantial ethnomedicinal diversity in coastal ecosystems, emphasizing the urgent need for conservation strategies, sustainable harvesting protocols, and systematic pharmacological validation to preserve indigenous knowledge while supporting rural healthcare and drug discovery initiatives.