Abstract: Stress among police officers is not new, but it has grown in scope and severity as modern societies become more complex and demanding. Police officers are routinely exposed to occupational hazards such as extended shifts, high workload, exposure to traumatic incidents, and constant interaction with the public under tense circumstances. These conditions make officers susceptible to mental health challenges such as burnout, depression, stress and anxiety. In Kenya, stress among police officers has been flagged as a pressing occupational health issue. Traffic police are on the frontlines of managing congestion, enforcing laws, and responding to accidents. Working extended shifts, often beyond the recommended 8 hours, leaves officers physically and mentally drained. Globally, stress management training has emerged as a proactive strategy to strengthen officers’ mental health resilience. This study aimed to assess the effectiveness of stress management training on mental health resilience among traffic police officers working extended shifts in Nairobi City County, Kenya. The study was informed by Cognitive Behavioral Theory. This study adopted a descriptive design, while the target population comprised all 740 traffic police and it employed stratified random sampling, and sample size was 260 traffic officers whose data was collected via questionnaires. The study results established that stress management training significantly 0.000 (p < 0.05) improves mental health resilience among traffic police officers in Nairobi City County. The study concludes that stress management training significantly enhances mental health resilience among traffic police officers working extended shifts in Nairobi City County. However, the persistent operational stressors such as long shifts, heavy workloads, traffic congestion, and exposure to road accidents, limit the full effectiveness of training. To enhance the effectiveness of stress management training and improve mental health resilience among traffic police officers, the national police service leadership should actively champion stress management training; traffic police officers themselves should be encouraged to take personal responsibility for their mental health resilience; the Ministry of Interior should regular updates it polices on mental health resilience and police welfare programs such as, rethinking shift patterns, staffing busy areas adequately, refresher courses, peer-support systems and ensuring officers have access to wellness resources. 

Key words: Stress, Stress Management Training, Mental Health Resilience, Police Officers