Zara - and other brands like Pull & Bear and Bershka - have promised to only sell sustainable clothes by 2025.
The company that owns these shops says all cotton, linen and polyester they sell will be organic, sustainable or recycled.
Zara has 64 UK stores, and its parent company has 7,490 shops worldwide.
Reacting to the news, Friends of the Earth told Radio 1 Newsbeat it would be "better for everyone if the industry sold clothes made to last."
Over the past few years, a lot of what we buy has been criticised for being fast fashion - clothes we barely use.
What will you see in the shops?
From next year, containers will appear in Zara stores to collect your old clothes so they can be reused or recycled into new items.