Up to 4,500 objects are being removed from the National Maritime Museum as part of a huge clear out.
Some items from the museum are going back to their original homes
The museum said it does not have enough room to show all of its 2.5m objects so it has decided to disperse or dispose of thousands of historic items.
The Museums Association said mistakes had been made in the past where objects deemed "unfashionable" became popular decades later.
But a museum spokesman said items were being distributed to other museums.
"Throw away is a terrible way to look at it," said the spokesman.
"What we do see, in the two and a half million items in our collection, is some things that can't be displayed, can't be researched or where we've got better quality items that better represent that particular feature.
"Not only do we clear out but we also collect and acquire."
The Museums Association is currently reviewing the way museums disperse of items in their collections.
An association spokeswoman said it was difficult to predict what may become popular in the future.
"People who work in museums are very conscious that they don't just have a responsibility to their visitors today but a responsibility to future generations, and that can be an incredible burden," she said.
"Terrible mistakes have been made in the past.
"In the early 20th Century quite a lot of museums disposed of their pre-Raphaelite paintings because they were so under-rated and so unfashionable then and now of course everyone thinks they're wonderful and museums wished they'd still had them."
Some items from the National Maritime museum will go back to the museums they originally came from.