Fangirls consist of the female fandom as opposed to male fanboys. This is often an important distinction if their behavior is considered different than men.

The sterotypical fangirl is sometimes a mirror of a fanboy. She is often in the slash or yaoi/shonen-ai fandom. Some argue these stereotypes come from the fanboy perception of women, which is often misogynistic or vindictive, especially if such women are not interested in them. Such conflict usually occurs when the subject matter they are equally interested in overlaps, such as when mostly male-aimed shōnen anime and manga invariably attract fans of yaoi, which is mainly female-aimed. Sometimes, fangirls are in the minority and are more put off by the behavior of the male fans themselves, who are surprised women are interested in the subject matter. In contrast, fangirls tend to tolerate male minority in their interest fairly well.

Another trait of fangirls and fangirlism is the existence of BNFs, or Big Name Fans. These are usually the best or most prolific writers, artists, or other creators of a fandom. BNF culture is particular to fangirls because of their extremely social and community orientened nature. In contrast, it is commonly assumed that fanboys are excessively anal retentive in regards to canon.

The existence of these BNFs can often cause clashes among the fandom, especially with large or well known fandoms and BNFs. Harry Potter's Cassandra Claire, famous for having been bought both an iPod and a laptop by her fans, is a good example.

See also fanon.