Background: Malaria is a major public health problem in Sub-Saharan Africa. Most of the infections are asymptomatic, affecting mainly pregnant women and children. Asymptomatic malaria can cause anaemia and adverse pregnancy outcomes, hence the need for routine screening at booking for antenatal care. Objective: To determine the prevalence of asymptomatic Plasmodium parasitaemia amongst pregnant women at booking for antenatal care and its effect on haematological indices. It also evaluated the influence of socio-demographic and obstetric factors on the occurrence of asymptomatic Plasmodium parasitaemia. Methodology: This cross-sectional study involved 216 pregnant women who booked for antenatal care between February and May 2017 in the University of Port Harcourt Teaching Hospital. Blood samples for Plasmodium parasites and full blood count were collected from all the participants. Data on socio-demographic and obstetric risk factors were obtained using a structured proforma. Data analysis was carried out using Statistical Package for Social Sciences version 20.0. Bivariate and multivariate analysis were performed and p-value of < 0.05 was significant.