INTRODUCTION: This study compared Polyvinyl Chloride (PVC) made vs Plaster of Paris (POP) made functional braces in the closed treatment of fractures of the humeral shaft. Outcomes examined were the rate of fracture union, radiographic alignment, DASH scores and the range of motion of the shoulder and elbow METHODS: This was a parallel randomized clinical trial conducted at the Corazon Locsin-Montelibano Memorial Regional Hospital from July 2016 to July 2017. All eligible patients were included and randomly allocated into PVC and POP treatment groups. All patients were followed-up on the 3rd, 6th, 10th, and 14th week for clinical and radiographic evaluation. RESULTS: There were 31 patients, 14 and 17 in the PVC and POP groups, respectively. The median rate of union in the PVC and POP groups were 10.50 and 10.00 weeks, respectively. The median varus and valgus angulation in the PVC and POP groups were 15.75° and 16.5°, respectively. The median anterior and posterior alignment in the PVC group was 1.7° and POP group was 9.6°. The median DASH score of the PVC and POP groups were 7.1 and 12.5, respectively. The median range of motion in the elbow was 135° for both groups. The median range of motion in the shoulder in the PVC group was 150° and POP group was 140°. CONCLUSION There was a high rate of union of humeral shaft fractures with acceptable functional outcome with the use of the PVC made functional brace compared to the traditional POP made functional brace.