Metalanguage is an important part of teacher talk in L2 classrooms. The present study examined the occurrence and type of metalinguistic terms in teacher feedback and their relationship with the patterns of learner uptake and the effectiveness of teacher feedback. A total of eight teachers and nine classes participated in the study. Four to six observations were made in each class, and two tailor-made individualized tests were administered to learners. The results revealed that: (1) the occurrence of metalinguistic terms varied notably with the type of feedback episodes (i.e. teacher-initiated, student-initiated and reactive); (2) the presence of metalinguistic terms was significantly related to both the frequency and successfulness of uptake, but the type of metalinguistic terms was only significantly related to the frequency of uptake, not its successfulness; and (3) metalinguistic terms in general were not significantly related to learners' performance in either the immediate test or the delayed test, but the type of metalinguistic terms was significantly related to the results of the delayed test.