The aim of the present study is to investigate the effectiveness of teaching emotional intelligence skills in strengthening emotional intelligence and improving the mental health of teenage girls who have low emotional intelligence. The research design is organized as a pre-test - post-test with a control group in the form of quasi-experimental research. The sampling method is judgmental. After selecting qualified people (girls, second year of high school, 16 and 17 years old, emotional intelligence below 90), they were randomly replaced in experimental and control groups (34 people in each group) and pre-test for both The group was implemented, then the training of emotional intelligence skills was applied to the experimental group. At the end, a post-test was taken from them. In order to evaluate the variables of the research, tools including demographic profile sheets, EQ-i emotional intelligence questionnaires and GHQ mental health were used. Also, independent t-test, dependent t-test, Pearson's correlation coefficient and regression analysis were used for data analysis. All stages of analysis were done with SPSS-13 software program. Results: Independent t-test pre-test in emotional intelligence and scales It did not show any significant difference in mental health scores. The results of the independent t-test to compare the difference between the pre-test and post-test emotional intelligence scores of the control and experimental groups concluded that the training significantly strengthened emotional intelligence (P<0.01). Trainings on strengthening the scales of intrapersonal intelligence, interpersonal intelligence, adaptability; Dealing with stress, general mood, has been significantly effective. Also, emotional intelligence skills training has significantly improved mental health (P<0.01). The results showed that emotional intelligence skills training can significantly strengthen emotional intelligence and improve the mental health of adolescent girls with low emotional intelligence.