Abstract: This research sought to find out whether the firm can be competitive and remain sustainable when other firms enter in the in-telecommunication sector and increase the highly competitive age. The study was guided by the following objectives; to investigate competitiveness of MTN Rwanda in telecommunication industry, to assess sustainability of MTN Rwanda in telecommunication industry, and to find out the relationship between competitiveness and sustainability of MTN Rwanda. The study used case study approach, mixt methods approach quantitative and qualitative were adopted to conduct the study. The targeted population of this research was 287 MTN Rwanda’ employees. 167 employees were selected purposively as sample size. The research used a case study approach to give an in depth understanding of competitiveness and sustainability of MTN Rwanda.