Background: The utilization of facility-based health care services was among the means to tackle the transmission of the COVID 19 and protection of better health. However, reluctance to the utilization of facility-based health care services has been reported to be a major problem everywhere in the globe. This study was to assess the utilization of facility-based health care and associated factors among adults in Oromia regional state, Ethiopia.Methods: Community-based cross-sectional studies were conducted using a quantitative approach. Data was collected from 2751 adults aged 18 years and above using an interviewer-administered structured questionnaire. The collected data were entered into Epi info version 7.2.0.1 and analyzed using STATA 15. Bivariate and multivariable binary logistic regression analyses were conducted to determine the association between the study variables. Odds Ratio with its 95%CI was calculated and P-Value < 0.05 was used as a cut-off point to declare the significance. Results: The overall utilization of facility based essential health care was 25.5% (95% CI: 24.6%, 26.4%). Agro-pastoralist (AOR 0.50, 95% CI; 0.50, 1.31), urban residence (AOR 0.66, 95% CI; 0.48, 0.92), Orthodox religion followers (AOR 0.58, 95% CI; 0.41, 0.81), and marital statuses in the widowed/divorced/ Separated category (AOR 0.45, 95% CI; 0.20, 0.99), were significantly associated with utilizations of facility based essential Health Care. Conclusions: Only 646 (25.5%) of respondents visited health facilities after the commencement of the COVID 19 pandemic. Activities to increase the utilization of essential health care services are crucial through appropriate information outlets.
