Wearing a wig cap is beneficial in holding the hair in place when wearing a wig, whether the hair is short or long. It also prevents the hair from breaking when a wig rubs against the scalp. If you have long hair and need to hold your hair back, it is the wig cap that secures the wig or the hair in place and prevents slipping. Wearing a wig cap also helps to maintain the cleanliness of the wig, as it separates the wig from the scalp. The cap keeps the hair flat so that no lumps or bumps change the shape of the wig.

Lace wigs and wig cap styles allow you to wear your hair in up-hairdos and high ponytails, as it has lace all around the perimeter. The cap will keep the lace wig from sliding and hold it securely in place, especially in women with longer hair. Another purpose for the wig cap in lace wigs is to give a natural part to the wig. Because of the cap, the hair can be parted anywhere throughout the wig to create a natural looking part. The wig cap replaces the need for a stocking cap under the lace wig.

Wig caps allow men who wear wigs or toupees to ensure a proper fit and to allow them to sit farther back on the head for a more natural look. Regardless of the cost of the wig, without the cap on the head to prevent slipping, the wig will not sit well. By applying the cap to the head and actually gluing the cap to the wig, the wig will look and feel more comfortable. Use a mono top cap, which is a cap that is handmade with see-through mesh at the top.

A wig cap is also used for permanent hair loss and total baldness conditions. A plaster mold of the head is made to provide a precise fit or suction to the head, ensuring a tight vacuum fit. Still, the cap can cause the head to become very warm and itchy during the summer months, when moisture may develop because of perspiration.

In a retail environment, where consumers try on wigs to purchase, the use of a wig cap for temporary purposes helps to serve as a buffer between the wig and the scalp. Most stores prohibit multiple people from wearing the same wig without properly covering the head first. The use of a temporary cap prevents any oils or chemicals from a previous customer who has tried on the wig and chosen not to purchase it to transfer them to another customer. Temporary caps are usually much thinner than ones that you would use for your daily wig styling and are meant to be disposed of after each use. The purpose is to keep the wig sanitary and free of any germs or conditions, such as dandruff. Salons provide temporary caps, or you may wish to purchase your own.