Background: Proper utilization of health data has paramount importance for health service management. However, it is less practiced in developing countries, including Ethiopia. Therefore, this study aimed to assess routine health information utilization and identify factors associated with it among health workers in the Illubabor zone, Western Ethiopia.Methods: A facility based cross-sectional study was conducted from March to June 2021 with a total of 423 randomly selected health workers. Data were collected using an interviewer-administered questionnaire that was developed based on the performance of routine information system management (PRISM) framework. We created composite variables for health workers' knowledge, attitude, abilities, and information utilization based on existing data. Multivariate logistic regression analysis was performed and the statistical association between the outcome and independent variables was declared using 95 percent CI and a P-value<0.05Results: About two-thirds or 279 health workers (66.0 percent, 95 percent CI: 61.3, 70.4) had good health information utilization. Two-thirds of health workers think organizational decision-making culture (67.1 percent, 95 percent CI: 62.6, 71.5) and facility managers' or supervisors' promotion of information use (65.5 percent, 95 percent CI: 60.9, 69.9) are positive. Over half of health workers (57.0 percent, 95 percent confidence interval: 52.2, 61.6) have a positive attitude toward data management, and the majority (85.8 percent, 95 percent confidence interval: 82.2, 88.9) believe they are competent of performing routine data analysis and interpretation activities. Only about two-thirds of health workers (65.5 percent, 95 percent CI: 60.9, 69.9) were proficient in data analysis and interpretation.Conclusions: The use of routine health information was higher than the national target and data from other literatures, yet an unacceptably large number of health personnel did not use information. As a result, efforts should be made to increase health workers' data management knowledge and skills, as well as the organizational culture of data utilization.