Background: Vitamin A deficiency (VAD) is a major contributor to child mortality in sub-Saharan Africa. Sustained control of VAD is essential to meet the Millennium Development Goal (MDG) for reduction of child mortality in Guinea. Since, twice yearly vitamin A supplementation (VAS), either coupled with National Immunization Days or stand-alone has been adopted as a key strategy to combat VAD in 6-59 months old children. Objectives. The objectives of this survey were to describe national. VAS coverage rates and related factors affecting VAS coverage among 6-59 months old Guinean children. Methods: In July 2003, a VAS coverage survey was implemented in Guinea. A cross-sectional random cluster survey was conducted to select Guinean children (n = 1950, 390 mother-child pairs per zone) aged 6-59 months. The country was divided into four agro-ecological zones with 30 clusters chosen per zone. Within each cluster, a random selection of 13 households with at least one child was carried out with random selection of one child per household. Data on characteristics-of children, receipt of VAS, caregivers' socio-economic characteristics, vitamin A knowledge and practices of caregivers were collected by questionnaire. Results: The national coverage rate of 68% is much lower than the official coverage rate of 93%. Middle Guinea, the region most affected by VAD, had the lowest coverage rate (58%). Conclusion: In order to increase overall VAS coverage and reduce regional disparities, it is suggested that mass VAS be organized on a regional level, prioritizing rural regions (Middle and Upper Guinea) and the city of Conakry.