An estimated two to three million annual deaths from vaccine preventable diseases (VPDs) are prevented through immunisation. Currently about 19.5 million infants miss out on routine immunisation globally. We carried out a study on the role of message content in persuasive communication on adoption of routine immunisation services. The study employed a mixed method research design. A sample of 384 caregivers was used. Data was collected using interviewer administered questionnaires and Key Informant Interviews. The key informants interviewed were taken with sub-county medical officer of health, health promotion officer and EPI coordinator. Both descriptive and inferential statistics were applied in the analysis. The study findings were that message content had positive influence on adoption of routine immunisation. The study recommended that routine immunisation messages be made frequently available, targeted and tailored to the caregivers. Secondly, the community should be involved in advocacy towards adoption of routine immunisation, to create ownership and adoption sustainability. Additionally, health workers should be motivated towards good practice in health worker-client communication, specifically, persuasive communication to build trust from the caregivers. The researcher recommends comparative studies should be conducted, comparing the well performing counties with Bomet County, Kenya.An estimated two to three million annual deaths from vaccine preventable diseases (VPDs) are prevented through immunisation. Currently about 19.5 million infants miss out on routine immunisation globally. We carried out a study on the role of message content in persuasive communication on adoption of routine immunisation services. The study employed a mixed method research design. A sample of 384 caregivers was used. Data was collected using interviewer administered questionnaires and Key Informant Interviews. The key informants interviewed were taken with sub-county medical officer of health, health promotion officer and EPI coordinator. Both descriptive and inferential statistics were applied in the analysis. The study findings were that message content had positive influence on adoption of routine immunisation. The study recommended that routine immunisation messages be made frequently available, targeted and tailored to the caregivers. Secondly, the community should be involved in advocacy towards adoption of routine immunisation, to create ownership and adoption sustainability. Additionally, health workers should be motivated towards good practice in health worker-client communication, specifically, persuasive communication to build trust from the caregivers. The researcher recommends comparative studies should be conducted, comparing the well performing counties with Bomet County, Kenya.