Malaria is a major global public health problem, with a particular burden of disease in sub-Saharan Africa including Ethiopia. Access to Long Lasting Insecticide Nets (LLINs) for at-risk populations, ensuring its appropriate utilization and identifying the barriers are important for malaria prevention, control and elimination. This study aimed to assess coverage, utilization and associated factors of Long Lasting Insecticide Nets (LLINs) among households in the Arsi Zone of Oromia Region, Ethiopia. Community-based cross-sectional study was conducted from October to December 2021. Multi-stage sampling technique was used to recruit 1250 households from five districts out of 21 Malarious districts in the Zone. Proportional allocations of households were done in each sampled kebeles and simple random sampling was used to draw the study participants. Data were collected by trained data collectors using a pre-tested structured questionnaire and observation. The collected data were exported to and analyzed using SPSS version 23. Variables with a p-value below 0.2 at bivariable logistic regression analysis were entered into the multivariable logistic regression model. We presented findings using an adjusted odds ratio with 95%CI at a p-value of less than 0.05. Out of the total of 1250 households 99.5% of surveyed owned LLINs and 27.1% of them had slept under the net the night before the survey. The factors associated with LLIN usage included being in the age range of 40 to 49 years (AOR; 1.82, 95%CI 1.01-3.25), preference for conical-shaped LLINs (AOR = 2.36; 95% CI: 1.33-4.18), not believing LLINs expired within 6 months (AOR 3.75, 95% CI 2.31-6.09), reporting a mosquito bite as a mode of malaria transmission (AOR = 2.46; 95%CI: 1.01-5.98), employed (AOR = 9.0; 95%CI: (4.22-20.02) and type of sleeping bed (AOR =: 17.4; 95% CI, 11.74-26.03). On the other hand, households with two and above sleeping rooms were less likely to use LLINs (AOR = 0.46; (95% CI: 0.23-0.88). Even though the ownership of Long Lasting Insecticidal Nets was high, the actual utilization was very low. Promoting the usage of LLINs utilization among those at most risk, through intensified health education activities will be helpful.