Well, for tax purposes you're only supposed to value your donated stuff at what it would actually sell for second-hand. Financially, you're better off selling the stuff. Personally, I think that holding a yard sale is a lot of work for the money and would rather just donate and take the tax deduction. If you're going to be selling big items anyway, you might want to have a yard sale. You'll still end up with a lot of unsold items to donate. Don't forget to get receipts for your donations.