Before you donate your used mattress, you need to make sure it is clean and in good repair. Organizations won't accept mattresses with visible stains, structural problems or tears.
In some areas, throwing away a mattress is illegal, meaning recycling and donation are your only options.
Charities like Salvation Army and Goodwill Industries usually don't take mattresses, due to hygienic concerns.
Missions, homeless shelters, crisis centers and halfway houses need a lot of beds and are usually happy to take a mattress donation.
Donate your old mattress to a recycler, where the fiber, steel, metal and foam can be separated then used to make new mattresses.
Whether you donate to a recycler or a charity, ask if they can pick up the mattress. Most will do so for free. Also, ask for a receipt, so you can write off the donation on your taxes.