Determinants of utilisation of intrapartum obstetric care services in Cambodia, and gaps in coverage. 
Facility delivery and skilled birth attendance are two of the most effective strategies for decreasing maternal mortality.  The objectives of this study were to further define utilisation of these services in Cambodia and to uncover socio-economic or location-specific coverage gaps that may exist.  We performed a cross-sectional analysis of the 2005 Cambodia Demographic Health Survey (CDHS) to determine prevalence, and determinants, of service utilisation.  Out of 6069 women aged 15-49 years, 77% delivered at home, three-fourths without a skilled birth attendant.  Poverty, lower education and rural residence were associated with the highest likelihood of poor utilisation of services.  Discussion.  While there has been an overall increase in facility deliveries and skilled birth attendance since 2000, improvements have been spread unevenly across the population, benefiting mostly urban, wealthier and better educated women.  While recent financing initiatives and health system developments appear to have further increased service utilisation since 2005, the extent of their reach to the most vulnerable populations, and their ultimate impact on maternal mortality reduction, remain to be elucidated.  Further expanding successful initiatives, particularly among vulnerable populations, is essential.  Longitudinal evaluation of ongoing strategies and their impact remains critical.