A Research Report Submitted to Mzumbe University - Mbeya Campus College in Partial Fulfillment of the Requirements for the Award of the Bachelor Degree in Human Resource Management (BHRM) at Mzumbe University.The study aimed to assess the impact of career development towards organizational performance, which was conducted at TANESCO Mbeya, the specific objectives is to Determine factors that influence career development on organizational performance, to identify criteria used for selecting employees for career development, to examine how career development affects the organization performance, and to examine the challenges faced by TANESCO in implementing career development programme to its workers. The study is vital because it helps to improve quality of service, helps to maintain productivity of the organization, and greater achievements of organization objectives. The researcher use case study design. A probability sampling and non-probability sampling techniques based on simple random sampling and purposive sampling is used in the study due to the nature of the title being conducted. The targeted population was 49 from which 40 as a sample size were selected to be respondents. A researcher use Primary data, were information are collected through interview and questionnaires methods from the employees. The data analyzed qualitative and quantitative where by explanation is used by analyzing qualitative data and simple descriptive statics used to analyze quantitative data. The findings presented in term of tables. The study finding showed that quality of service improved was a sign of organizational performance and greater achievement of organizational objectives, head of department recommendation and new technology requirement where the criteria used in selecting employees in career development, Personal and social satisfaction is achieved is effects of career development, financial constraints and Lack of awareness is a sign of challenges faced career development at TANESCO Organization. The study recommended that Trainings and seminars should be added to workers to be skilled at once, a thing which saves time and add more productivity to an organization. One chain of command, TANESCO Officers should have one chain of command when they provide instructions and directions to their employees on developing their careers and in relation to organization rules and regulations.