This study examined the effect of internal marketing on employee job satisfaction: a case of Grant Carlcare (T) Limited in Mwanza City. It was guided by three objectives which are: to determine the relationship between internal marketing and employee job satisfaction, to identify the contribution of internal marketing factors in employee job satisfaction and to identify the internal marketing factors responsible for job dissatisfaction among employees. The study surveyed 60 employees using self administered questionnaires, an interview was also held with selected employees. This study finding realized that there is a relationship between internal marketing and employee job satisfaction at Carlcare (T) Limited due to its importance in establishing proper channels of communication between management and employees. Internal marketing contributes in developing positive attitudes among employees towards their job, improves the quality of interactive and external market delivery and also increase employee’s perception on management’s caring for their needs which in turn increase job satisfaction level. The study also identified internal marketing factors like employee motivation, internal communication and empowerment as factors responsible for job dissatisfaction among employees. The study recommends that Carlcare (T) Limited should establish effective plans for the development of internal marketing initiatives, particularly directed towards enhancing internal communication between management and employees, motivating employees and promote smooth communication between employees and management. The company should increase to motivate employees by providing them with benefits, incentives, promotion, rewards, empowerment and integrated internal communication.