As superior job performance leads to rewards, bonuses, and promotions, it may be viewed as the ultimate goal of the employee in both military and non-military settings. Therefore, this chapter undertakes an in-depth assessment of job performance in a green context by describing the details of empirical studies involving job performance. The concept of job performance is the organization’s assessment of the extent to which an employee’s skills, talents, and capabilities contribute to the enhancement of firm competitiveness and social benefits. The formal assessment procedure within the organization consists of annual reviews followed by longer-term reviews by multiple parties. The use of annual reviews is to uncover deficiencies in performance that may be rectified before they become seriously detrimental. The use of assessments by multiple parties is to ensure objectivity by evaluating performance from different perspectives. In this book, job performance is green performance, or the employee’s contribution to environmental sustainability goals of the organization.