The objective of this collaborative research is to evaluate the impact of a pedagogical intervention that combines flexible grouping and explicit instruction of reading comprehension strategies. The development of competencies is spread over a two years interval. However, despite this quite long implementation period, several Quebec students still had not completely overcome their difficulties in reading comprehension. The study was conducted at an elementary school on the outskirts of Montreal. 76 students participated in the research. Four teachers and one learning specialist planned and experimented these monthly 90-minute classes, which were implemented ten times during the school year. The results show a noticeable reading comprehension improvement, particularly, for students with learning difficulties.