Objectives: to identify self-efficacy and self-esteem levels in undergraduate nursing students and to verify the mutual relationship between these constructs and with sociodemographic variables. Method: a cross-sectional study, with a sample of 264 students from two universities. Self-esteem and self-efficacy were measured by the Brazilian versions of the Rosenberg's Self-Esteem and of the General and Perceived Self-Efficacy scales, respectively. Results: a predominance of moderate to high self-efficacy was identified, with a mean score of 35.29 and moderate self-esteem, with a mean of 23.48. Self-efficacy was associated with the male gender, priority option in the college entrance examination by nursing, satisfaction with the course and absence of overload, besides correlating positively with age and self-esteem. Conclusion: self-efficacy and self-esteem levels were moderate/high and moderate, respectively. These constructs have shown a mutual relationship and assume an indispensable role both in the individual's personal life and in the professionalization process. These findings point to the need to strengthen mental health in this population, especially in vulnerable students (female, activity overload, dissatisfaction with the course and low self-esteem and self-efficacy), in order to foster their sense of value and the belief in their abilities.

Objective: to evaluate the impact of the “Strengthening Self-Esteem” intervention proposed by the Nursing Interventions Classification, conducted through the use of Facebook, on the self-esteem and self-efficacy levels of nursing undergraduates. Method: quasi-experimental study carried out in two Higher Education Institutions. The sample consisted of 74 students. Two data collection tools were applied before and after the intervention: Rosenberg Self-Esteem Scale and General and Perceived Self-Efficacy Scale. The students were submitted to the intervention for ten sessions. Posts were made in private profile created on Facebook and consisted of positive messages, reflective texts and pictures, all supported by the persuasive resources of Bandura’s theoretical framework. Results: of the 264 students who answered the pretest, 74 (28.03%) participated in the interventions and the post-test. Rosenberg self-esteem (p=0.026) and self-efficacy (p=0.001) scores after the intervention were significantly higher than those obtained before, confirming the effectiveness of the intervention. Conclusion: the “Strengthening Self-Esteem” intervention was effective for improving students’ self-esteem and self-efficacy levels. Such interventions help spread knowledge and build mentally healthier individuals.