BACKGROUND Skin laxity and crepiness of the arms is a cosmetic concern that before the advent of noninvasive skin tightening technologies could only be treated with surgery. Ultrasound-based technologies deliver energy to the dermis which causes neocollagenesis and neoelastogenesis to rejuvenate the skin. OBJECTIVE This study evaluates and compares the efficacy of a high-intensity, parallel beam ultrasound-based skin tightening (HIUS) device with microfocused ultrasound with visualization (MFU-V) for improvement of upper arm skin laxity and crepiness. MATERIALS AND METHODS A prospective, single-center, blinded, split-body, randomized clinical study investigated HIUS and MFU-V for improvement of upper arm skin laxity and crepiness. Subjects received a single treatment to the upper arms. RESULTS Fourteen female subjects completed the study. Assessments compared Day 30 and Day 90 follow-up visits with baseline. HIUS was as effective as MFU-V in improving arm laxity and crepiness. Investigators and subjects rated improved arm laxity/crepiness at Day 90. Most subjects were satisfied with the improvement of arm laxity/crepiness. There was no statistically significant difference in pain scores observed between the HIUS and MFU-V. The MFU-V treatment took more time to perform than the HIUS treatment. CONCLUSION High-intensity, parallel beam ultrasound-based skin tightening was effective and delivered results with high patient satisfaction for improving upper arm skin laxity/crepiness.