Background. The National Travel Health Network and Centre (NaTHNaC) introduced a program of registration, training, standards, and audit for yellow fever vaccination centers (YFVCs) in England, Wales, and Northern Ireland (EWNI) in 2005. Prior to rolling out the program, NaTHNaC surveyed YFVCs in England. Objectives. To reassess the practice of YFVCs in 2009, 4 years after the institution of the NaTHNaC program, to identify areas for ongoing support, and to assess the impact of the program. Methods. In 2009, all YFVCs in EWNI were asked to complete a questionnaire on type of practice, administration of travel vaccines, staff training, vaccine storage and patient record keeping, use of travel health information, evaluation of NaTHNaC yellow fever (YF) training, and resource and training needs. Data were analyzed using Microsoft Excel® and STATA 9®. Results. The questionnaire was completed by 1,438 YFVCs (41.5% of 3,465 YFVCs). Most YFVCs were based in General Practice (87.4%). In nearly all YFVCs (97.0%), nurses advised travelers and administered YF vaccine. An annual median of 50 doses of YF vaccine was given by each YFVC. A total of 96.7% of nurses had received training in travel medicine, often through study days run by vaccine manufacturers. The internet was frequently used for information during travel consultations (84.8%) and NaTHNaC's on-line and telephone advice resources were highly rated. Following YF training, 95.8% of attendees expressed improved confidence regarding YF vaccination issues. There was excellent adherence to vaccination standards: ≥94% correctly stored vaccines, recorded refrigerator temperatures, and maintained YF vaccination records. Conclusions. In the 4 years since institution of the NaTHNaC program for YFVCs, there has been improved adherence to basic standards of immunization practice and increased confidence of health professionals in YF vaccination. The NaTHNaC program could be a model for other national public health bodies, as they establish a program for YF centers.