Cornwall Partnership Trust was caring for seven patients with coronavirus in hospital as of Wednesday, figures show.
NHS England data shows the number of people being treated in hospital with Covid-19 by 8am on May 24 was up from two on the same day the previous week.
There were four beds occupied by patients with Covid-19 four weeks ago in Cornwall Partnership NHS Foundation Trust.
Across England there were 3,116 people in hospital with Covid as of May 24, with 81 of them in mechanical ventilation beds.
Nationally, the number of hospital patients with Covid-19 has decreased by 35% in the last four weeks, while the number on mechanical ventilators has decreased by 20%.
The figures also show that nine new patients with Covid were admitted to hospital in Cornwall Partnership NHS Foundation Trust in the week to May 22. This was up from five in the previous seven days.