Make a list. You want to be as specific and detailed as possible. If it's a situation where your roommate "borrowed" clothing or other items, write down the date when she borrowed them and the circumstances surrounding the lending of the items. This is necessary in case your roommate tries to claim that you gifted the items to her.

Gather receipts and bank statements if necessary. You might need to provide substantial proof that you purchased the items that your roommate is withholding. Gather any receipts you have, as well as credit card statements and past bank statements that might serve as proof that you paid for an item. If you have pictures of yourself with the items, these can help as well.

Speak to your roommate. First, try to calmly ask your roommate to return your items. Call her and ask for your items back as politely as possible. Explain to her that it is illegal to keep any of your personal belongings and you can prove they are yours. If she puts you off or indicates that she is not going return your belongings, write her a letter. Indicate exactly what you want her to return. Include copies of your receipts if you have them to let her know that you have proof that the items are yours. Send her the letter via certified mail.

Contact a lawyer. Even if you don't want to pay a lawyer to represent your case, you can opt for just a single consultation with a lawyer so he can advise you regarding further actions you can take to recover your items. A lawyer can also write a formal letter to your roommate requesting that she return all the items by a certain date, noting that if she doesn't, you are going to take legal action. Sometimes, a strongly worded legal letter can be enough to persuade someone to cooperate because she won't want to go to court.

Take it to court. If worse comes to worse and you cannot get back your personal property, you can take the matter to court. You can either file a complaint with your district court or take your case to small claim's court. The amount for which you can sue in small claims court varies among states. For example, as of 2013, you can sue in a Maine small claims court if the total value of your property is $6,000 or less, according to Pine Tree Legal Assistance. Once you file the appropriate paperwork and serve your complaint on your roommate, you will both have to attend a court hearing where you can show your evidence. After hearing from both sides, a judge will determine if you get your items back.