To determine prevalence and factors associated with intimate partner violence (IPV) among pregnant women seeking antenatal care. This was a cross-sectional study conducted at Kisumu District Hospital, Kenya amongst randomly selected pregnant women. A structured questionnaire was used to collect data. Participants self-reported about their own IPV experience (lifetime, 12 months prior to and during index pregnancy) and associated risk factors. Data were analyzed using Epi-info. The mean age of the 300 participants was 23.7 years. One hundred and ten (37 %) of them experienced at least one form of IPV during pregnancy. Psychological violence was the most common (29 %), followed by sexual (12 %), and then physical (10 %). Women who experienced IPV during pregnancy were more likely to have witnessed maternal abuse in childhood (aOR 2.27, 95 % CI = 1.05-4.89), been in a polygamous union (aOR 2.48, 95 % CI = 1.06-5.8), been multiparous (aOR 1.94, 95 % CI = 1.01-3.32) or had a partner who drank alcohol (aOR 2.32, 95 % CI = 1.21-4.45). Having a partner who attained tertiary education was protective against IPV (aOR 0.37, 95 % CI = 0.16-0.83). We found no association between HIV status and IPV. IPV is common among women seeking antenatal care at Kisumu District Hospital. Health care providers should be alerted to the possibility of IPV during pregnancy in women who witnessed maternal abuse in childhood, are multiparous, polygamous, have a partner who drinks alcohol or has low level education. Screening for IPV, support and referral is urgently needed to help reduce the burden experienced by pregnant women and their unborn babies.