In line with WHO objectives, the Lao Government is committed to eliminate measles by 2012. Yet from 1992 to 2007, the annual incidence of measles remained high while the vaccination coverage showed a wide diversity across provinces. A descriptive study was performed to determine factors affecting compliance with vaccination against measles, which included qualitative and quantitative components. The qualitative study used a convenience sample of 13 persons in charge of the vaccination program, consisting of officials from different levels of the health care structure and members of vaccination teams. The quantitative study performed on the target population consisted of a matched, case-control survey conducted on a stratified random sample of parents of children aged 9-23 months. Overall, 584 individuals (292 cases and 292 controls) were interviewed in the three provinces selected because of low vaccination coverage. On the provision of services side (supply), the main problems identified were a lack of vaccine supply and diluent, a difficulty in maintaining the cold chain, a lack of availability and competence among health workers, a lack of coordination and a limited capacity to assess needs and make coherent decisions. In the side of the consumer (demand), major obstacles identified were poor knowledge about measles immunization and difficulties in accessing vaccination centers because of distance and cost. In multivariate analysis, a low education level of the father was a factor of non-immunization while the factors of good compliance were high incomes, spacing of pregnancies, a feeling that children must be vaccinated, knowledge about immunization age, presenting oneself to the hospital rather than expecting the mobile vaccination teams and last, immunization of other family members or friends' children. The main factors affecting the compliance with vaccination against measles in Laos involve both the supply side and the demand side. Obtaining an effective coverage requires upgrading and training the Expanded Programme on Immunization (EPI) staff and a reinforcement of health education for target populations in all provinces. (C) 2010 Elsevier Ltd. All rights reserved.