Mobile phones enable people to keep in touch with their families and friends. It makes easy the day to day activity of peoples around the world. The aim of this research is to investigate demographic factors influencing consumers__ampersandsignrsquo; life style on mobile phone usage in Dilla City, Ethiopia. This study evaluates the effect of demographic factors specifically consumers__ampersandsignrsquo; age, education, income, and occupation on mobile phone usage. The research methodology used in this study is both qualitative and quantitative approaches. 381 customers were surveyed by using purposive sampling technique. The target population of the study included businessmen, employees in government offices, teachers, and students. Primary data was collected through structured questionnaire. Secondary data were gathered from books, research studies, various governmental and nongovernmental organizations reports, and on line resources. Descriptive statistics and One-Way Analysis of Variance was employed to analyze the data. The results of the study revealed that significant difference exist between life style on mobile phone usage and consumers__ampersandsignrsquo; occupational status and monthly income. On the other hand, the research found out that life style on mobile phone usage was not varied by age group and educational level of respondents. The research concluded that consumers__ampersandsignrsquo; make their purchase decisions by evaluating their life style and demographic factors in mobile phone usage. Hence, the findings of the study provided that companies and manufacturers need to consider demographic factors that affect mobile phone usage in order to meet the current demand of consumers in Dilla.