Age-related differences in upper extremity (UE) kinematics during activities of daily living are poorly understood. To develop control databases for clinical studies, a greater understanding of UE mechanics and potential changes in motion as a function of age is needed. The purpose of this research was to examine age-related differences in three- dimensional UE kinematics between young adult and pediatric groups while performing activities of daily living. Fifteen young adults (n = 15) aged 18-24 years (mean age: 20.2 years) and fifteen pediatric participants (n = 15) aged 7-9 years (mean age: 8.3 years) participated in the study. An eight-camera Vicon MCam system was used to record UE motion during the performance of three tasks: drinking, eating, and a simulated perineal care task. Significant differences in mean maximum joint angles were found between the age groups for all three tasks. No significant differences were found in kinematics data between the dominant and non-dominant arms for any task. Differential UE movement patterns may exist due to differences in experience with the tasks, anthropometrics, techniques used to complete the task, and/or neuromaturational levels. These results emphasize the need for age-matched control data for clinical studies of UE motion.