Intimate partner violence (IPV) against women negatively impacts infant health. However, its impact on infant's biology, in particular on telomere length (TL) is unknown. The aim of this study was to examine the association between IPV against women before childbirth and cord blood TL in their newborn. A total of 774 pregnant women in the 20th-24th week of gestation were recruited at a public hospital in Hong Kong. The mothers' exposure to IPV before childbirth, demographic characteristics, obstetric outcomes, health and mental health were measured at the time of recruitment and 4 weeks after childbirth. Umbilical cord blood was collected by midwives at the time of delivery. The newborn TL was quantified using quantitative PCR method and expressed in T/S ratio (the ratio of telomere repeat copy numbers to single-copy gene numbers). After adjusting for a number of confounding variables, the mothers' exposure to any IPV before childbirth (β = -0.08, 95% CI = -0.14, -0.01) was associated with shorter TL. Specifically, psychological abuse against women before childbirth (β = -0.08, 95% CI = -0.15, -0.02) and sexual abuse against women before childbirth (β = -0.22, 95% CI = -0.43 to -0.01) were significantly associated with reduced newborn TL. This study is the first to provide evidence of an association between IPV against women before childbirth and TL shortening in their newborns. Through TL- dependent transcription and epigenetic mechanisms, our finding suggests maternal exposure to IPV may exert a life-long impact on the offspring's health.