Objective: To determine the relationship between the psychological Bienestar (BP) and the nursing competence of nursing staff in a Unidad de Cidados Intensivos (ICU). Methodology: Quantitative, relational, cross-sectional and prospective, a census was conducted among 31 ICU nurses at the ISSSTE (Institute of Security and Social Services of State Workers), Aguascalientes. Carol Ryff’s “Psychological Well-Being Scale" and Ritta Meretoja's "Nursing Competence Scale" were used. Results: 67.7% of nurses working in the ICU have a high level of BP, and 83.9% have a very good level of nursing competence. Through a correlation test by Rho Spearman, he obtained that there is no relationship between the level of nursing competence of those who work in the ICU with their level of BP. Conclusion: There is not enough statistical evidence to say that there is a relationship between nursing competence and BP. The BP does not affect nursing competence, despite being a service of high demand for care and adequate attention and care is provided to the critical patient.