Training and manpower development is indispensable to the success of any organisation as efficiency in the productivity and performance of an organisation hinges on the knowledge, attitude and skills of the employees of the organisation. This dissertation evaluates the effect of training and development on workers' performance in Nigerian College of Aviation Technology (NCAT), Zaria. One of the difficulties of training and manpower development is how to enhance, and measure the effectiveness of training and manpower development programme. The subsidiary objectives of the study include: the contribution and impact of staff training to the enhancement of the job performance of NCAT staff; and to ascertain whether post-training evaluation of the job performance of NCAT staff improves training effectiveness. To achieve the objectives of the study, the study adopted the survey research method. While primary data was sourced using questionnaires administered to randomly selected employees of the various Training Schools and Service Departments of the College; text books, journals and internet materials were employed as sources of secondary data. The research made the discovery that though training enhances the job performance of employees, performance evaluation of trained employees does not enhance, improve or guarantee training transfer. Furthermore, it was found that the effectiveness of training and manpower is being threatened and undermined as there are cases of improper identification of employees' training needs, and selection criteria of trainees being compromised. Therefore, we recommend the need for proper diagnosis of the training needs of employees before employees are shortlisted or recommended for training programmes. Training evaluation techniques such as interview, observation, etc. are also recommended after a given training programme so as to detect and rectify any deviation from training objectives that are clearly outlined before the commencement of the training activities.