Most jobs involve some degree of stress. The nature of the duties of the police exposes them to tremendous pressure, which leads to stress. These stress factors are serious and challenging. This study examines the effect of stress on effective policing in Nigeria. The causes and consequences of stress in the police were investigated and discussed. Factors such as training, role conflict, information dissemination, workload, performance appraisal and lack of equipment were major causes of stress. In contrast, task performance, hyper vigilance, physical illness and burnout were identified as consequences of stress in the Nigerian Police. Recommendations were made on how to improve the work environment of the police to minimize the effects of stress.