Drawing on second language (L2) motivation constructs modelled on Dörnyei's (2009) L2 Motivational Self System, this study explores the relationship between language testing experience and the motivation to learn English among young adolescents (aged 12-15) in South Korea. A 40-item questionnaire was administered to middle-school students (N = 341) enrolled in a private language school ("hakwan"). Exploratory factor analysis (EFA) identified five salient L2 motivation factors. These factors were compared to four learner-background characteristics: gender, grade level, L2 test-preparation time, and experience taking a high-stakes university-level language test. The results suggest that second language motivation, based on the L2 motivation factors identified as most salient in this educational context, was significantly associated with the amount of time spent preparing for language tests and experience taking a high-stakes language test intended primarily for university-entrance purposes. Young South Korean adolescent learners' testing experiences and their motivation to learn English are discussed in relation to the social consequences of test use and ethical assessment practices.