Background: In many developing countries maternal morbidity and mortality are challenging issues. Increasing the knowledge of women about the danger signs of pregnancy is the first essential step to reduce the adverse outcomes of pregnancy and delay in deciding to seek obstetric care, which in turn improves early detection of obstetric complications. This study aimed to assess knowledge of danger signs of pregnancy and health-seeking action among pregnant women. Methods: A health facility-based cross-sectional study was conducted in public health facilities from 1 March 2017 to 30 April 2017 on 414 pregnant mothers. The data were collected by systematic random sampling technique, entered into a computer using Epi data 3.5, and analyzed using Statistical Package of Social Sciences version 20.0. Bivariate and multivariable logistic regression analyses were done to estimate the crude and adjusted odds ratio with a confidence interval of 95% and a P value of less than 0.05 considered statistically significant. Results: This study identified that 57.2% of pregnant women had good knowledge of the danger signs of pregnancy. Pregnant women who are found in the age group of 25–29 [adjusted odds ratio (AOR)=3.35, 95% CI=1.13–9.96], and ≥30 years (AOR=8.11, 95% CI=2.23–29.45), mothers who live in urban area (AOR=5.26, 95% CI=1.96–14.15), primary education (AOR=4.85, 95% CI=2.07–11.41), secondary and above educational level (AOR=6.90, 95% CI=3.28–14.49), employed mother (AOR=5.18, 95% CI=1.65–16.27), being multigravida (AOR=7.24, 95% CI=3.86–13.58), knows that danger signs of pregnancy may cause severe complications (AOR=9.94, 95% CI=5.23–18.93), knew what to do if they faced danger signs of pregnancy (AOR=3.37, 95% CI=1.14–9.93), knew when did they go to a health facility if they faced danger signs of pregnancy (AOR=3.97, 95% CI=1.67–9.47) and faced at least one danger signs of pregnancy in current pregnancy (AOR = 5.40, 95% CI=1.46–19.99) were significantly associated with knowledge of danger signs of pregnancy. The proportion of mothers who experienced danger signs of pregnancy was 27 (6.5%) and among them, 21 (77.8%) had an appropriate health-seeking action, which is visiting a health facility. Conclusion: In this study area, the knowledge of pregnant women about the danger signs of pregnancy was low, while the practice of the mothers in response to danger signs of pregnancy was encouraging. Therefore, it is needed to the empowerment of women by increasing access to get an education, especially for rural women.