The demand for methods to ensure safe oral consumption of food and liquids in order to prevent aspiration pneumonia has increased over the last decade. This study investigated the safety of swallowing care selected by adding ultrasound-based observation, evaluated its efficacy, and determined effective content of selected swallowing care. The study employed a pragmatic quasi-experimental research design. Participants were 12 community-dwelling adult patients (age: 44–91 years) who had experienced choking within 1 month prior to the study. After the control phase, in which conventional swallowing care was provided, trained nurses provided ultrasound observation-based swallowing care for a minimum period of 2 weeks. Outcome measurements were compared across three points, namely T1—beginning of the control phase, T2 and T3—before and end of the intervention phase. The mean durations of intervention were 30.8 days in the control phase and 36.5 days in the intervention phase. Pneumonia and suffocation did not occur in the control phase or the intervention phase. The safe intake food level and the food intake level score significantly improved during the intervention phase (p = 0.032 and 0.017, respectively) by adding eating training based on the ultrasound observation. However, there was no significant improvement in the strength of the muscle related to swallowing by the selected basic training. Our results suggest that swallowing care selected based on the ultrasound observation, especially eating training, safely improved safe oral intake among community-dwelling adults with swallowing dysfunction.