According to the IRS, for donations made after August 17, 2006, clothing and household goods given to charity must be in “good condition or better” in order to take a valid tax deduction. Note: the IRS does not define “good condition”.
A limited exception to the IRS ruling allows you to deduct a single item in “less than good condition” if the item is appraised at more than $500. It’s interesting to note that in 2003 clothing represented 48% of tax deductions from donations.