This study is part of a larger research project investigating the effects of using metalinguistic reflection integrated into a communicative class as a way of promoting second language acquisition among French-speaking Grade six (i.e. 10-11 year old) ESL learners (n=81). Even though metalinguistic reflection is thought to promote language development, only a few studies have empirically investigated its effects (Armand, 2000). Different ways of promoting metalinguistic reflection can be identified in the literature. Allison (1998), for instance, used diaries for this purpose. The questions addressed in this article are: Can diary writing promote metalinguistic reflection among grade six ESL learners? If so, what kind of metalinguistic reflection do these learners produce in their reflections? Does this reflection differ according to the type of students who produce it? The data were obtained from diaries and tests of metalinguistic reflection ability. Students were assigned to one of three groups (Enriched, Regular, Control) and were measured at three different periods of measurement (pre-test, immediate post-test and delayed post-test). Enriched students more frequently wrote explicit comments about L2 in their diaries. All students noticed elements of the L2. Differences in their ability to report about language remained the same throughout the study. The amount of metalinguistic reflection produced by the Control group increased dramatically at the delayed post-test.