WH Smith has launched a review of the price of goods sold in hospitals after toothpaste was found on sale for £7.99.
The newsagent which has outlets at 129 hospitals across the country was also found to be selling essentials such as nappies and mouthwash at a heavily marked up price.
In an interview with The Telegraph, Simon Stevens, head of the NHS said: "These retailers should think again about jacked-up prices which affect poorly patients, their family visitors, and hardworking hospital staff."
A WH Smith spokesperson said: "There is a small number of ranges like toiletries which we stock in hospitals for customers' convenience which are not sold in our high street stores.
"Despite having relatively low sales of these products we aim to set our prices as competitively as possible.
"We are currently reviewing the prices of all such items to ensure they comply with this policy and will take the appropriate action where they do not."
At one outlet at Pinderfields Hospital, part of the Mid Yorkshire Hospital trust, a 75g tube of Colgate toothpaste was on sale for £7.99, when the same product can be bought for 99p in Superdrug and £1 in Sainsbury's.
Speaking to the Telegraph, Rachel Power, chief executive of the Patients Association, said: "When people are unwell and in hospital, and therefore unable to go elsewhere with any ease, they should be able to expect retailers not to exploit their situation for profit."
Additional reporting by Press Association.