<p>To receive adequate protection against influenza, some children 6 months through 8 y old need two doses of influenza vaccine in a given season. Currently, only half of those receiving the first dose receive a second. Our objective was to assess vaccine hesitancy and influenza disease and vaccine knowledge, attitudes, and beliefs among caregivers of children who received the first of their two needed doses. As part of a national-randomized control trial of second dose text-message influenza vaccine reminders (2017-2018 season), a telephone survey collected caregiver and index child demographic information. Each child had received the first of two needed influenza vaccine doses. Caregivers completed a measure of general vaccine hesitancy - the five-question Parent Attitudes About Childhood Vaccines Survey Tool (PACV-5) - and questions about influenza infection and vaccine. We assessed associations between participant demographic characteristics, vaccine hesitancy, and influenza beliefs and calculated the standardized proportion of caregivers endorsing each outcome using logistic regression. Analyses included responses from 256 participants from 36 primary care practices in 24 states. Some caregivers (11.7%) reported moderate/high vaccine hesitancy and many had misperceptions about influenza disease and vaccine. In multivariable models, no single variable was consistently associated with inaccurate knowledge, attitudes, and beliefs. These results demonstrate that caregivers whose children received the first dose of influenza vaccine may still be vaccine hesitant and have inaccurate influenza beliefs. Pediatricians should consider broadly addressing inaccurate beliefs and promoting vaccination even after caregivers agree to the first dose.</p>