Employees' job satisfaction is an old concept in industrial relations and is influenced by a number of factors. Since the promulgation of the Constitution of Kenya 2010, some of the government functions which used to be under the central government have since been devolved to the county governments. These functions include the Ministry of Health, Ministry of Water, Ministry of Agriculture and Ministry of Public works and roads among others. Employees working in these ministries, among others, had their functions devolved to the county governments. The deployment to the counties had adverse effects among employees as exemplified by strikes of the employees of the Ministry of Health. The main objective of this study was to assess the effect of selected job motivational factors on civil servants' job satisfaction within government devolved functions in Nakuru County. The target population was 1912 employees working in the devolved functions. The sample size of the study was 320 systematically picked across the devolved functions. The study used a close ended questionnaire as the main data collection tool. Both Pearson's correlation and regression analyses were used to establish whether the selected motivational factors were related to the exiting level of employees' job satisfaction. The study established that procedural justice and interactional justice contributed significantly to employees job satisfaction compared to communication and supervision.