The aim of this study was to evaluate the construct validity and feasibility of a multidimensional electronic pain diary (e-Ouch©) in adolescents with juvenile idiopathic arthritis (JIA). Two descriptive studies with repeated measures were conducted between January and December 2005. Participants were drawn from a large metropolitan rheumatology clinic in a university affiliated pediatric tertiary care centre. In Study 1, 76 adolescents with active arthritis recorded their pain three times a day for 2 weeks using the e-Ouch©. In Study 2, 36 adolescents recorded their pain three times a day for 1 week before and 2 weeks after joint injections. Adolescents in both studies completed multiple measures to determine the construct validity and feasibility of the e-Ouch©. Adolescents reported mild levels of pain intensity, unpleasantness, and interference as well as stiffness, and mild to moderate levels of fatigue. e-Ouch© average weekly pain unpleasantness and interference scores were higher in adolescents with higher pain intensity scores. Correlations between average weekly pain ratings on the e-Ouch© and scores from: (a) recalled least, average and worst weekly pain, (b) health-related quality of life and pain coping, and (c) disease activity were as predicted. Pain ratings were significantly lower following joint injections with effect sizes in the low to moderate and moderate to high ranges at the first and second week post-injection, respectively. These findings provide evidence of the construct validity and feasibility of the e-Ouch© electronic diary in adolescents with JIA. Use of real-time data capture approaches should be considered in future studies of chronic arthritis.