Background <p>The number of vulnerable older adults is expected to continue to increase, highlighting the urgent need to develop comprehensive social care measures to address frail older adults’ needs. The objective of this study is to examine the effects of a community health nurse-led, multi-faceted, group-based frailty prevention program on functional capacity, frailty, and metabolic health among community-dwelling older adults.</p> Methods <p>This quasi-experimental study uses a single-group, pretest-posttest design. Community dwelling older adults (≥ 65 years) were recruited from 13 counties using convenience sampling (<i>N</i> = 92). The 8-week program consisting of health education and exercise sessions was conducted by two per community health nurses with groups of 5 to 10 participants per county.</p> Results <p>This study included 92 participants (mean age: 76.98 ± 5.43); 89.13% female. The intervention resulted in significant improvements in functional capacity, as measured by the TUG test time and grip strength (categorical) (t = 7.47, 95% CI [1.21, 2.08], <i>p</i>-value &lt; 0.001; χ²=22.51, <i>p</i>-value &lt; 0.001). Frailty showed significant improvements in both continuous (t = 7.17, 95% CI [1.34, 2.24], <i>p</i>-value &lt; 0.001) and categorical indicators (χ²=29.71, <i>p</i>-value &lt; 0.001). Among metabolic health indicators, only blood sugar levels showed significant improvement (χ²=8.95, <i>p</i>-value &lt; 0.001).</p> Conclusions <p>Although the absence of a control group limits the ability to draw direct causal inferences, improvements in health-related outcomes were observed to be associated with the intervention. Community health nurse-led, multi-faceted group interventions that are implemented based on a high understanding of county resources and participants may be an effective approach for developing health promotion programs for vulnerable older adults in community settings.</p> Clinical Trial Number <p>Not applicable.</p>