Knowing how to read and write are basic skills that individuals must master, at the beginning of schooling, in order to continue learning and to become able to live in an increasingly literate and technological society. Both learning difficulties and behavior problems are issues, frequently associated, that affect the acquisition of academic and social skills, which lead to school failure and trigger possible mental health problems that start during childhood and might last until adulthood. Thus, the aim of this study was to raise the prevalence of emotional and behavioral disorders in first graders with learning difficulties, according to the evaluation of their guardians and teachers. 599 first grade students took part in the first phase (screening of children with low school performance through a scale specifically developed for this purpose). In this phase, 107 students (17.86%) were classified with poor school performance, with boys showing more difficulties than girls. In the second phase (screening of emotional and behavioral disorders in children with learning difficulties according to the evaluation of teachers and guardians), 105 students were evaluated by teachers through the Strengths and Difficulties Questionnaire -SDQ. The teachers also filled out a form that indicated in which learning domain (reading, writing and/or mathematics) the lowperforming students had more difficulties with. Descriptive statistical analyses were performed for the treatment of data obtained in phases 1 and 2, and after that, the Student's T-Test was applied to verify whether there were significant differences between groups (girls and boys) and informants (teachers and guardians) regarding the prevalence of mental health problems. 76 students out of 105 were also evaluated by their guardians through the SDQ. According to the teachers' evaluation (n=105), 65 students (61.90%) were classified in the abnormal range of the SDQ, whereas 74 (70.48%) presented significant difficulties in all of the three learning domains. According to the evaluation of the guardians (n=76), 47 students (61.84%) were classified in the abnormal range of the SDQ. The highest percentage of children classified in the abnormal range, whether in teachers' or guardians' assessments (n=76), occurred in the Hyperactivity Subscale, 49 (64.47%). There were no statistically significant differences between girls and boys with learning difficulties regarding the prevalence of emotional and behavioral disorders. A moderate convergence index was observed between the evaluations of teachers and guardians: 41 cases (53.95%). The highest convergence rate was related to the total SDQ: 33 children (80.49%) were classified in the abnormal range of the SDQ by both informants. The subscale with the highest concordance rate was Hyperactivity, 25 children (60.98%) classified in the abnormal range. Regarding the divergent results, the highest non-agreement index among the informants refers to the Prosocial Behavior Subscale (p < 0.001). Overall, the results of this study poi...