Pre-frail older adults require appropriate exercise to enhance muscle strength as well as upper limb functionality. We developed a handheld vibrator and evaluated its effectiveness in enhancing muscle strength compared to conventional exercises among pre-frail community-dwelling older adults. Thirty-one pre-frail older adults (aged 75.5 ± 5.1 years) were recruited and randomly allocated to a vibration group (VG) and control group (CG). The VG underwent 20 minutes of vibration (frequency: 30 Hz, amplitude: 5 mm, horizontal vibration) using a handheld vibrator as well as 40 minutes of conventional exercise. The CG received 60 minutes of conventional exercise only. The primary outcome was muscle strength assessment (kg), and the secondary outcome included activities of daily living and instrumental activities of daily living scores. The comparisons between the outcome measures revealed no significant differences at the baseline level. Muscle strength of the dominant (ß = 2.49, p = 0.002) and non-dominant (ß = 1.89, p = 0.02) wrist flexion, brachioradialis (ß = 3.8, p = 0.01), and biceps brachii (ß = 3.02, p = 0.02) in the dominant upper limbs was significantly increased among the VG. The vibration intervention can enhance muscle strength in the upper limbs among pre-frail older adults.