Background. Antiretroviral therapy (ART) initiation is critical for the prevention of mother-to-child transmission (PMTCT) of HIV. Objectives. To quantify factors that were barriers or facilitators to the initiation of ART in pregnant HIV-infected women in Swaziland. Methods. We conducted a cross-sectional survey in HIV-infected women with at least one antenatal care (ANC) visit, who had delivered in maternity wards between April and August 2013 in Swaziland. Variables collected included intrapersonal, interpersonal and organisational factors. Logistic regression models were used to calculate univariate and adjusted multivariate measures of association between ART initiation and the independent variables. Results. Among the 163 pregnant women who were eligible for ART, 110 (67.5%) were initiated on ART by the time of delivery. The most commonly cited reason for not initiating ART (n=53) was women not being ready to initiate life-long treatment (24.5%). On multivariate logistic regression, favourable perceptions of the benefits of ART (adjusted odds ratio (AOR) 3.04; 95% CI 1.55 -5.96) and presence of partner support (AOR 4.75; 95% CI 2.11 -10.67) remained significantly and independently associated with ART initiation. Conclusion. ART initiation among ART-eligible pregnant women in Swaziland was independently associated with the presence of partner support and favourable perceptions of the benefits of ART. Stronger counselling and education for pregnant women and male involvement strategies need to be implemented as universal life-long ART for all HIV-infected pregnant women is implemented. Factors associated with the lack of antiretroviral therapy initiation among eligible HIV-positive pregnant women in Swaziland Prior to 2013, antiretroviral therapy (ART) was recommended by the World Health Organization (WHO) for HIV-infected pregnant women with CD4 cell counts of <350 cells/µL or those who were at WHO clinical stage III or IV Women who did not meet these criteria,were advised to use one of two options. Option A: antepartum zidovudine, with single-dose nevirapine during labour, and a 7-day zidovudine/lamivudine 'tail' alongside daily infant nevirapine during breastfeeding. Option B: ART during pregnancy and through cessation of breastfeeding to prevent mother-to-child HIV transmission (PMTCT.) [1] Many countries, including Swaziland, chose to implement option A; a CD4 cell count was performed on all women identified to have HIV infection to determine those who should be initiated on life-long ART for both maternal health and PMTCT. In Swaziland, 88% of facilities that provide antenatal care (ANC) services also provide PMTCT services.[2] In 2009, 73% of women attending ANC facilities were tested for HIV, and 88% of HIV-infected pregnant women received a complete course of PMTCT prophylaxis in 2009. [3] However, a review of the data in the Early Infant Diagnosis (EID) database in Swaziland at the time of the introduction of option A guidelines, showed that ~50% of HIV-infected women who were eligible for ART actu...