Measles is a prime candidate for global eradication. Explicit goals to control or eliminate the disease have already been agreed upon by many countries and regions. One of the key concerns in determining the appropriateness of establishing the measles eradication goal is its potential impact on routine immunization services and the overall health system. To evaluate the impact of accelerated measles elimination activities (AMEAs) on immunization services and health systems, a study was conducted in six countries: Bangladesh, Brazil, Cameroon, Ethiopia, Tajikistan, and Vietnam. Primary data were collected through key informant interviews and staff profiling surveys. Secondary data were obtained from policy documents, studies, and reports. Data analysis used mainly qualitative approaches. The study found that the impact of AMEAs varied, with positive and negative implications in specific immunization and health system functions. On balance, the impacts on immunization services were largely positive in all six countries, particularly in Bangladesh, Brazil, Tajikistan, and Vietnam; negative impacts were more significant in Cameroon and Ethiopia. Although weaker health systems may not be able to benefit sufficiently from AMEAs, in more developed health systems, disruption to health service delivery is unlikely to occur. Nevertheless, in none of the six countries was there an explicit objective to use AMEAs to help remove health system bottlenecks and strengthen system capacity. Opportunities to strengthen routine immunization services and the health system should be actively sought to address system's bottlenecks so that benefits from the measles eradication activities as well as other health priorities can be optimized.