Vaccine hesitancy is an obstacle to achieving high vaccination rates for COVID-19. Current knowledge on vaccine uptake is mostly based on hypothetical intention to vaccinate surveys. We compared intention to vaccinate and real-world vaccine uptake among 511 soldiers in a military unit during an unrestricted, on-site COVID-19 vaccine rollout. Soldiers were offered group lectures, on-site consultations and primary care office visits, discussing concerns on vaccination with a primary care physician. Overall, 359 (70.3%) soldiers participated in the group lectures, 33 (6.5%) in on-site consultations and 19 (3.7%) attended primary care visits. Overall, 459 (89.8%) of 511 soldiers vaccinated for COVID-19. Of the 90 soldiers initially refusing, 38 (42.2%) had agreed to receive a vaccine. On-site COVID-19 vaccine rollout joined with primary care communication interventions may maximize vaccine uptake within a young-adult community. Future studies should evaluate the effectiveness of these efforts across different populations in a controlled and comparative manner.