Background and rationale: In the Lao PDR, shortage of blood for transfusion for use in hospitals is an important and challenging problem, which has not been adequately resolved. This is due to the very low number of voluntary blood donation by the general population. Many factors may contribute to the low number of voluntary blood donation of Lao people, which we do not all know and understand. Results: Eight hundred and ninety-eight subjects were enrolled in the study and interviewed (449 cases and 449 controls). The median (range) age of the respondents was 26 years (17 – 40). Factors significantly associated with voluntary blood donation were males (OR = 1.71; 95% CI = 1.31-1.23, P= 0.001), being single (OR = 2.01; 95% CI = 1.52-2.65, P<0.001), having a positive attitude toward voluntary blood donation (OR = 3.17; 95% CI = 2.37-4.22, P<0.001), convenience in traveling to and short distance from home to blood donation centre (OR = 2.35; 95% CI = 1.73-3.20, P=0.01), (OR = 1.67; 95% CI = 1.25-2.22, P=0.001), respectively, and having received information on blood donation from any channels (OR = 1.88; 95%CI = 1.38-2.55, P<0.001). Another important but not statistically significant reinforcing factor for voluntary blood donation was blood donation during important occasion (birthday, marriage anniversary and valentine’s day). Conclusion This study suggested that (1) voluntary blood donation campaign should be carried out continuously and focus on young people at educational institutions and (2) it is very vital that mobile blood donation teams continue their activities regularly in order to ensure that blood demand in hospital can be achieved.