More than 425,000 people across the county have received their initial dose of the COVID-19 vaccine.
However, some sites are experiencing up to 60 no-shows per day.
Lincolnshire has two main vaccination centres, one at the Lincolnshire Showground and one at the Princess Royal Sports Arena in Boston, where staff can vaccinate 1,000 people a day.
A spokesperson for Lincolnshire’s Clinical Commissioning Group said the main reason people aren’t showing up is because of confusion in the booking system. They said: “People book via the National Booking System, then get the opportunity to book in (perhaps sooner) via their local GP practice, but don’t cancel their original appointment.”