Study aim: This study will be conducted to investigate the effectiveness of stress management training on job stress, psychological well-being, self-efficacy, and intolerance of uncertainty among employees of the Irancell Call Center. Design: A randomized, controlled, single-blind, parallel-group clinical trial was conducted involving 30 male call center employees. Randomization was performed using a random number table. Settings and conduct: This study will be conducted as a randomized controlled trial at the Iran cell call center. Participants meeting the inclusion criteria who provide consent will be assigned to either the experimental or control group via a randomization process. A single-blind design will be employed, meaning participants will remain unaware of the study's objective and their group assignment. Participants/Inclusion and exclusion criteria: Inclusion criteria: Age 30–50 years, score ≥40 on the Job Stress Questionnaire, informed consent, and basic reading and writing ability. Exclusion criteria: Severe psychiatric disorders, receiving psychological or psychiatric treatment during the past six months, previous stress management or life skills training, and history of substance abuse or alcohol dependence. Intervention groups: Training sessions will be conducted in a group format, with one 90-minute session per week for eight weeks. The stress management content is based on the book A Practical Guide to Cognitive-Behavioral Stress Management (Antony et al., 2007) The sessions include stress concepts, progressive muscle relaxation, diaphragmatic breathing, mental imagery, cognitive restructuring, self-relaxation, modification of maladaptive thoughts, and adaptive coping strategies. The final session includes exercise review and post-test administration. Main outcome variables: Job stress, psychological well-being, self-efficacy, intolerance of uncertainty.