摘要:Abstract Background Justification of intimate partner violence (IPV) has several implications, including reduced likelihood of help-seeking, increased experiences episodes of partner abuses, and poor health status and outcomes. However, in Papua New Guinea (PNG), where IPV is among the highest globally, little is known about factors influencing IPV justification among women in union. This study aimed at examining the prevalence of IPV justification and associated factors among women in union in PNG. Methods Data from the nationally representative cross-sectional demographic and health survey conducted among women aged 15–49 years during 2016–2018 in PNG were used. In all 9,943 women aged 15–49 years who were married or cohabiting during the survey were included. Bivariate and multivariate logistic regressions were performed and the results reported as crude odds ratios (cOR) and adjusted odds ratios (aOR) with 95% confidence intervals (CI). Results Overall, almost 7 in 10 women (68.9%, 95%CI:68.0–69.9) justified IPV. Multiple regression analysis revealed that co-habitation (aOR: 1.33, 95%CI: 1.17–1.50, p < 0.001), polygyny (aOR: 1.36, 95%CI: 1.20–1.53, p < 0.001), exposure to television (aOR: 1.24, 95%CI: 1.08–1.42, p = 0.002) and richer wealth status (aOR: 1.19, 95%CI: 1.01–1.40, p = 0.035), significantly increased the odds of justifying IPV. We found significantly lower odds of IPV justification among women aged 45–49 years (aOR: 0.53, 95%CI: 0.37–0.77, p = 0.001) and those with higher level of education (aOR: 0.56, 95%CI: 0.42–0.74, p < 0.001). Conclusion The prevalence of IPV justification was high among women in union in PNG. Women’s justification of IPV was associated with socio-demographic and economic factors. Our findings call for appropriate strategies including public education and empowerment programmes that target IPV in PNG. Moreover, strategies and interventions to address IPV justification should target the women’s socio-economic and demographic contexts that influence IPV justification.