BackgroundChildhood vaccination is an effective way to prevent serious childhood illnesses, but many children do not receive all the recommended vaccines. There are various reasons for this; some parents lack access because of poor quality health services, long distances or lack of money. Other parents may not trust vaccines or the healthcare workers who provide them, or they may not see the need for vaccination due to a lack of information or misinformation about how vaccinations work and the diseases they can prevent.Communication with parents about childhood vaccinations is one way of addressing these issues. Communication can take place at healthcare facilities, at home or in the community. Communication can be two-way, for example face-to-face discussions between parents and healthcare providers, or one-way, for instance via text messages, posters or radio programmes. Some types of communication enable parents to actively discuss vaccines and their benefits and harms, as well as diseases they can prevent. Other communication types simply give information about vaccination issues or when and where vaccines are available. People involved in vaccine programmes need to understand how parents experience different types of communication about vaccination and how this influences their decision to vaccinate.ObjectivesThe specific objectives of the review were to identify, appraise and synthesise qualitative studies exploring: parents' and informal caregivers' views and experiences regarding communication about childhood vaccinations and the manner in which it is communicated; and the influence that vaccination communication has on parents' and informal caregivers' decisions regarding childhood vaccination.Search methodsWe searched MEDLINE (OvidSP), MEDLINE In-process and Other Non-Index Citations (Ovid SP), Embase (Ovid), CINAHL (EbscoHOST), and Anthropology Plus (EbscoHost) databases for eligible studies from inception to 30 August 2016. We developed search strategies for each database, using guidelines developed by the Cochrane Qualitative Research Methods Group for searching for qualitative evidence as well as modified versions of the search developed for three related reviews of effectiveness. There were no date or geographic restrictions for the search.Selection criteriaWe included studies that utilised qualitative methods for data collection and analysis; focused on the views and experiences of parents and informal caregivers regarding information about vaccination for children aged up to six years; and were from any setting globally where information about childhood vaccinations was communicated or distributed.Data collection and analysisWe used maximum variation purposive sampling for data synthesis, using a three-step sampling frame. We conducted a thematic analysis using a constant comparison strategy for data extraction and synthesis. We assessed our confidence in the findings using the GRADE-CERQual approach. High confidence suggests that it is highly likely that the review finding is a reasonable repres...