ObjectivesA lack of safe healthcare waste management (HCWM) practice poses a risk to healthcare staff, patients and communities. In low-income countries like Ethiopia, studies on the level of safe HCWM practices in private healthcare facilities are limited. This study was designed to assess the level of good HCWM practice and associated factors among health workers in private health facilities.MethodsAn institution-based cross-sectional study was conducted in the Ilu Aba Bor zone, South West Ethiopia. A random sample of 282 health workers from 143 private health facilities was included in the study. Data were collected using a pretested structured questionnaire that included sociodemographic characteristics, healthcare factors, knowledge assessment and an observation checklist adapted from WHO guidelines. The collected data were entered into EpiData V.3.1 and analysed with SPSS V.25.0. Multivariable logistic regression analysis was used to identify factors associated with HCWM practice. Variables with a p value of <0.05 at 95% CI were declared significant.ResultsMore than half (58.7%) of private-sector health workers had good HCWM practice. The presence of the HCWM committee (adjusted OR (AOR)=9.6, 95% CI 4.5 to 20.6), designated healthcare waste storage site (AOR=3.0, 95% CI 1.5 to 6.5), reading the HCWM manual (AOR=4.4, 95% CI 2.2 to 9.0) and having good knowledge of HCWM (AOR=2.6, 95% CI 1.06 to 6.15) were factors associated with good HCWM practice.ConclusionAbout three out of five health workers in private healthcare facilities were practising good HCWM. The presence of an HCWM committee, waste management utilities, reading HCWM guidelines and knowledge of health workers were the identified factors. Health workers should read guidelines to improve their knowledge, and the presence of committees and waste management utilities in private clinics should be followed to ensure compliance with safe HCWM practice.