Maternal mortality and morbidity is a crucial public health concern. Every year, more than half a million women die from pregnancy-related causes and majority of these deaths occur in sub-Saharan Africa. This study explored socio-demographic factors, knowledge and attitude as determinants of antenatal care services utilization in Gesusu Hospital, Kisii County, Kenya. Cross-sectional research design was used. The study was conducted among pregnant women of reproductive age attending antenatal care clinic at Gesusu Hospital. Fisher’s et al. (1998) formula was used to determine the required sample size of 268 respondents. Quantitative data was collected using a pre-tested, semi-structured interviewer-administered questionnaire and checklist. Data was analyzed, presented and stored using SPSS version 20. Bivariate correlation and regression was done for the independent and dependent variables. Presentation was done using tables and bar graphs. The results showed that none of the independent variables was strongly associated with the dependent variable. The study concluded that there was poor utilization of ANC services; none of the socio-demographic characteristics examined was a true influencer of utilization of ANC services; general awareness on ANC was low; and, that there was an attitudinal problem towards the recommended number of ANC visits. It’s thus recommended that comprehensive longitudinal studies are done to help in better understanding of the underlying factors for late prenatal attendance and incomplete utilization of the services offered during antenatal care in order to improve their uptake.