The majority of developing countries do not follow the WHO’s emphasis on replacing harmful and ineffective traditional practices with evidence-based clinical treatment. In these countries, harmful or ineffective practices are routinely used as part of routine care during labor and delivery, while beneficial procedures are not used for the majority of laboring mothers. However, it is critical to use evidence-based practices while giving therapy since they improve care quality, save costs, increase patient and family happiness, and promote professional progress. To assess the magnitude of non-recommended (harmful) intrapartum practices among obstetric care providers in public hospitals in southern Ethiopia, 2023. An institution-based cross-sectional study was conducted from January 30, 2023, to February 30, 2023, in public hospitals in the Gamo and Gofa zones. An observational checklist and a self-administered questionnaire were used to gather data. Using odds ratio of 95% C, bivariate and multivariable logistic regression was used to discover factors related with the outcome variable during data analysis using SPSS version 27. A P-value of less than 0.05 and I were regarded as statistically significant. The magnitude of harmful intrapartum practice was 60.6% (95% CI: 53.25–68.5). Lack of internet access (AOR = 10.1, 95% CI: 4.93–21.1), a few years of work experience (AOR = 6.21, 95% CI: 3.1–12.5), and not being trained on evidence-based intrapartum practices (AOR = 4.01, 95% CI: 1.94–7.95) were statistically significant with harmful intrapartum practices. Evidence-based practice can be improved by promptly providing obstetric care providers with ongoing training and standards for intrapartum care.