This study aimed to identify the effects of internal makerting to customer loyalty. Despite influences of organizations to promote internal marketing tools to employees it has been hard to satisfy them due poor deliverance of marketing tools to employees in the organizations, this study aimed to identify ways which the employees are motivated, and how they create loyalty to customers. This study was conducted in Mwanza region at Air Tanzania airline offices, and the general objective was to examine effects of internal marketing on customers loyalty in Tanzania airline industry along with specific objectives which were to evaluate how training can raise the morale of internal markets, to assess on how empowerment of employees leads to provision of perceived services, and to identify how compensation of employees can lead customers to frequently use the airline company. Data was collected through the use of questionnaires tools and interview guides. The study used descriptive research design,and there was use of mixed approaches where there was the use of both qualitative and quantitative approaches,the analysis was done through the use of SPSS for quantitative approach and the use of semi-structured method for qualitative approach, the study comprised a sample of 31 respondents. Findings of the study, revel that Air Tanzania management is not effectively promoting internal marketing tools to satisfy its employees in order to increase their working morale moreover it was found out that the organization has few expertise for training employees, short learning frequency and training durations,and another problem was a small amount of compensation which led to destroying customer loyalty with the organization. Based on the findings the researcher concludes that internal marketing in Air Tanzania should increase into more level and recommends that the organization should practice internal marketing tools effectively so as to increase efficiency in the organization and reach stated organization goals.