This research explores how picturebooks can enhance ecocritical awareness and sustainable attitudes among 97 primary school children aged 8-9 in a Spanish school. The study includes 24 reading sessions in three formats: individual, small group, and adult-mediated. The selection of the corpus for children's readings aligns with theoretical studies focusing on an ecocritical approach to children's literature, a scholarly perspective that has gained prominence in recent decades. Results indicate that adult-mediated sessions are more effective than individual or small-group readings, fostering greater emotional and cognitive engagement. While students generally showed an ecocentric perspective, an anthropocentric view of sustainability persisted. The study highlights that, although guided reading is beneficial, a more integrated and multidimensional educational approach is needed to cultivate a regenerative consciousness. The educator's role is crucial for guiding students toward deeper, more meaningful ecocritical understanding.