This research assessed metacognitive mechanisms such as planning, self-regulation and evaluation, inherent in the reading and writing processes. The authors designed two tests that were intended to determine and describe different levels of the above mentioned metacognitive mechanisms in pre-school and primary school children. Thirty-six children (18 girls and 18 boys) between 5 and 10 years old, who attended the same middle socioeconomic level school were assessed. The tests allowed the examination of the following variables: reading and writing metacognitive mechanisms, reading comprehension and writing. The study also examined how these variables were affected by the children‘s gender and grade. Results showed that all of the children were classified in any of the levels of metacognitive development. The study also found that the four assessed variables were related with one another; as expected, school grade and the variables were also related. On the other hand, the results didn’t show a significant correlation between gender and the four variables studied.