INTRODUCTION: The disease burden and mortality related to Non-communicable Diseases (NCD) increased in the last couple of decades in Ethiopia. As a result, an estimated 300,000 deaths per annum were due to NCD. According to a World Health Organization report, 39% of the total deaths in Ethiopia were attributable to NCD. Rapid urbanization characterized by unhealthy lifestyles such as tobacco and/or alcohol use, physical inactivity, low fruits and vegetable consumption, and overweight drive the rising burden of NCD. However, studies on risk factors for NCD and associated variables are limited among working adults in Eastern Ethiopia. Therefore, this study aimed to examine the magnitude of the risk factors of NCD and associated factors among working adults in Eastern Ethiopia. METHODS: A cross-sectional study was carried out among 1,200 working adults in Eastern Ethiopia that were selected using a simple random sampling technique from December 2018 to February 2019. Data were collected following the World Health Organization Stepwise Approach to NCD Risk Factor Surveillance (WHO STEP) instruments translated into the local language. A total of five risk factors were included in the study. The Negative Binomial Regression Model was used to determine the association between NCD risk factor scores and other independent variables. Adjusted incidence rate ratio (AIRR) with a 95% Confidence Interval (CI) was used to report the findings while the association was declared significant at a p-value of less than 0.05. STATA version 16.1 was used for data clearing, validating and statistical analysis. RESULTS: Totally, 1,164 (97% response rate) participants were employed for analysis. Overall, 95.8% (95% CI: 94.4-96.7%) of the participants had at least one of the five risk factors of NCD. Furthermore, the proportion of participants that had all NCD risk factors was 0.3%. Among the participants, 47.5% were alcohol drinkers, 5.1% were current smokers, 35.5% were overweight, 49.1% exercise low physical activity, and 95% had less than five portions of fruits and vegetables intake per day. Higher risk factor scores were associated with those of advanced age (AIRR = 1.24; 95% CI: 1.01-1.53 in 35-44 age group and AIRR = 1.28; 95% CI: 1.01-1.62 in 45-54 age group), and the ones who are higher educational level (AIRR = 1.23; 95% CI: 1.07-1.43 for those who have completed secondary school and AIRR = 1.29; 95% CI: 1.11-1.50 for those who have completed college education). CONCLUSION: The overwhelming majority (95.8%) of the participants had at least one risk factor for non-communicable diseases. The risk score of non-communicable diseases was higher among those with advanced age and who completed secondary and above levels of education. In a nutshell, the finding shows the need for lifestyle modification and comprehensive non-communicable diseases prevention programs for working adults in Eastern Ethiopia.