Emotional Literacy (EL) is a well-designed, field-tested curriculum that enhances social, emotional, and academic learning. A total of 565 students, 53% female, from 17 elementary schools, participated in the study. Approximately half of the students participated in the eight-week-long EL program, while the other half was in control conditions. Both the experimental and control group fulfilled the same set of trait and ability emotional intelligence measures in three timepoints: pre-, immediately after, and six months after the program. The effect of the EL program was different for girls and boys at different measurement points. Boys placed in experimental group improved their scores at both post-treatment measurements, meaning that they rated themselves and felt more emotionally competent after being a part of the EL program. Emotional understanding improved consistently with time, measured with both the Vocabulary of Emotions Test (VET) and Test of Emotional Understanding (TEU), regardless of the participation in the EL program. The effect of maturation was slightly more visible in girls, and girls had consistently better scores on the VET and TEU tests than boys. The feedback from school psychologists working with children was positive; they agreed that the children responded well to the activities and willingly participated.