Pediatric patients, hospitalization in a pediatric intensive care unit (PICU) is not merely a situation requiring physical treatment, but also an experience that has significant psychosocial effects. This project was designed to evaluate the effect of a mood journal intervention on anxiety levels, mindfulness, and emotion regulation skills in conscious pediatric patients aged 9-14 years in a pediatric intensive care unit. An emotion journal is a supportive tool that allows children to express the experiences they have during the day, the emotions they feel, and their reactions to these emotions in a structured format. It is anticipated that this practice may help children develop their abilities to recognize, express, and regulate their emotions; it may also reduce their anxiety levels related to the intensive care process. Children admitted to the pediatric intensive care unit who are conscious, able to communicate, and meet the inclusion criteria will be assigned to the intervention and control groups using a randomization method. At the start of the study, both groups will be provided with the Child and Parent Information Form, the Child and Adolescent Mindfulness Scale, the Emotion Regulation Scale for Children and Adolescents, and the State Anxiety Scale for Children will be administered to both groups. The intervention group will participate in an emotion journaling program for 5 days, approximately 30 minutes per day, while the control group will receive routine clinical care. Data will be analyzed using the SPSS 30.0 statistical software; descriptive statistics, normality tests, parametric or non-parametric group comparison tests, and correlation analyses will be performed. As a result of the project, it is expected that the emotion journaling intervention will reduce children's anxiety levels, increase their mindfulness, and support their emotion regulation skills. It is anticipated that the findings will contribute to the development of implementable, low-cost, and child-centered psychosocial care interventions in pediatric intensive care units.