Introduction: HIV / AIDS are a workplace issue that mainly affects adult in the working age group of 15 to 49 years. The study will have significant effect for improving strategies, programs and services related to prevention practice of HIV/AIDS for factory workers at the Hawasa Industrial Park. Objective: To assess HIV prevention practice and associated factors among factory workers of Hawasa Industrial Park, SNNRS, South Ethiopia, 2019. Method: Institution based cross-sectional study was conducted on 636 factory workers of Hawasa Industrial Park on February, 2019 by using mult-stage sampling method. Data was entered into computer using the Epi-data software version 3.1 and exported to SPSS software version 22 for cleaning and for more analysis. Multiple logistic regressions were analyzed for possible predictor’s variable to identify factor associated with HIV prevention practice and to control for potential confounders. Statistical significance was taken as p<0.05. RESULT: This study found that the magnitude of overall HIV prevention practice among Hawassa Industrial Park workers were 79.3%. The participants who had more than two sexual partners were 74% less likely to have HIV prevention practice than those who had one sexual partner in the last twelve months (AOR=0.26;95%CI=0.11,0.58;P=0.001). The workers who had the experience of alcohol intake in the last twelve months were 51% less likely to have HIV prevention practice when compared to those who had no the experience of the alcohol intake (AOR=0.49;95%CI=0.25,0.95;P=0.03). Additionally, monthly income were negatively associated with HIV prevention practice (AOR=0.22; 95%CI=0.07, 0.76; P=0.01). Conclusion: The magnitude of condom utilization and be faithful to one sexual partner was below the report of EDHS 2016. The monthly income, living arrangements, number of sexual partner and alcohol consumption had significant effect on HIV prevention practice of factory workers. The government should implement the institution based outreach program which makes the target group involved as fully as possible in design and implementation of the program.