SUMMARYBackground: Many studies show that the vast majority of Nigerian women register for antenatal care late and that the determinants may differ from those found in developed countries. Objective: To determine the reasons for late booking among women presenting at the antenatal clinic of a major tertiary hospital in the Niger Delta, Nigeria Design: A cross sectional questionnaire based survey. Setting: A large tertiary hospital in the Niger delta, Nigeria Participants: Pregnant women registering for antenatal care after 14 weeks gestation. Results: The majority of respondents were aged 20-39 years (97.1%), quarters were primigravidae and 25 % of the women belonged to the upper socioeconomic class. Seventy three point six percent booked in the second trimester and 26.4% in the third trimester. Of the women who had given birth before, 80% had booked late in at least one previous pregnancy. More than three-fifth of the women (65.6%) booked late due to ignorance or misconceptions of the purpose of, and right time to commence antenatal care. Conclusion: The findings of this study suggest that most women book late because of a belief that there are no advantages in booking for antenatal care in the first three months of pregnancy. This seems to be because antenatal care is viewed primarily as curative rather than preventive in the study population. Research is needed to determine the best approaches for health education programmes to correct the misconceptions about antenatal care.