This study was designed to investigate whether the threshold level hypothesis (Cummins, 1976, 1979) could be applied to a three-language-in-contact school situation. The learning of three languages at school is becoming more and more commonplace throughout the world, some cases in Europe being reviewed. One of these three-language-in-contactschoolsituations is that of the Basque Country, a bilingual Community wherein both Basque and Spanish are official languages, and therefore taught at school. English is taught as a foreign language. The sample was made up of 252 students; 126 of them enrolled in Grade 5 (10-11-year-olds) and who were in their second year of learning English at school, and 126 enrolled in Grade 8 (13-14-year-olds) and who were in their third year of learning English at school. The participants completed Basque, English, and Spanish tests, as well as a background questionnaire and Raven's Progressive Matrices Test. The dependant variable was measured via a test of metalinguistic abilities. The threshold hypothesis could be applied either by establishing a third threshold or by maintaining the two original ones. The results showed that the maintenance of the original parameters on which the threshold hypothesis is based was more adequate than the proposal of establishing three thresholds.