The Mount Rungwe Nature Forest Reserve (MRNFR) is one of the biodiversity hotspots in the southern highlands of Tanzania. The reserve serves as a water catchment, endowed with a relatively high endemism and diversity of wild flora and fauna. Despite these vital resources, there is a significant interaction between the MRNFR and the adjacent community. However, the details on the benefits obtained by local communities from the conservation efforts, the anthropogenic threats to the reserve, the challenges faced by communities, and the involvement of the communities in the conservation of the MRNFR are not well documented. The current study aimed to determine the shared benefits, costs, challenges and involvement of the adjacent community in the conservation of the MRNFR. Data were collected using semi-structured questionnaires, focus group discussions (FGD), and key informant interviews (KII). Data analysis was performed using the Statistical Package for Social Sciences (SPSS) version 26, while graphical presentation was done by using Microsoft Excel computer software. The results show that the community benefits including; supervised firewood collection, controlled bee-keeping, and availability of clean water varied significantly across the study area at (F = 382.991, df = 2, p < 0.0001). The anthropogenic threats reported by the respondents adjacent to the MRNFR varied significantly at (z = 2.3259; p = 0.020) of which firewood collection was the leading (80%). The different challenges reported by the respondents adjacent to the MRNFR and the presence of problem animals was the leading (77%). The community reported getting involved in different conservation activities and was highly involved in making firebreaks (73%). The study found that, while the adjacent community suffers from problematic animals including kipunji and wild dogs, they largely benefit from the ecological services including clean water. The situation calls for more collaborative efforts between the community and conservationists to strengthen conservation while developing the well-being of the communities adjacent to MRNFR.