Background: Intimate partner physical violence is a common global phenomenon. About 30.00% and 38.83% of women in the world and in sub-Saharan Africa experienced physical violence by their partner respectively in 2013. Though intimate partner violence has serious adverse health consequences, there is limited information about partner violence during pregnancy in Ethiopia. Therefore, the aim of this study was to assess the prevalnce of physical intimate partner violence during pregnancy and associated factors among women attending antenatal care in Shire Endaselassie town, Tigray, northen Ethiopia Methods: A facility based cross-sectional study was conducted from May 3 to July 6, 2015. Four hundred and twenty-two pregnant women attending three public health facilities were included using systematic sampling technique. In addition, twenty-two purposely selected key informants were interviewed. The data collectors and supervisors were trained on all data collection processes. Data were entered to Epi-Info version 7.1.2.00 and exported to SPSS version 20.00. Logistic regression was used to identify factors associated with intimate partner physical violence. Statistical significance was declared at p < 0.05. Qualitative data were categorized into themes and triangulated with the quantitative results. Results: The prevalence of intimate partner physical violence in pregnancy was 20.6% (CI = 16.70, 24.90). Age at first marriage greater than or equal to 17 years (AOR = 4.42, CI = 2.07, 9.42), women with no formal education (AOR = 2.78 CI = 1.10, 7.08), rural dwellers (AOR = 2.63 CI = 1.24, 5.58), intimate partners with no formal education (AOR = 2.78 CI = 1.10, 7.08) and intimate partner alcohol consumption (AOR = 3.8 CI = 1.85, 7.82) were factors associated with intimate partner physical violence towards pregnant women. Conclusion: Nearly one fifth of women surveyed experienced intimate partner physical violence during pregnancy. Early marriage, rural dwelling, intimate partner alcohol consumption, and educational status were associated with intimate partner physical violence during pregnancy. Urgent attention to women's rights and health is essential at all levels to alleviate the problem and its risk factors in Tigray regional state of Ethiopia.