Onychotillomania, defined as self-induced trauma to the nail unit, either by picking or pulling at the nails, affects 0.9% of the population. It may lead to severe irreversible nail dystrophy, melanonychia, or infections. Although no large clinical trials have assessed the efficacy of treatments, cognitive-behavioral therapy, physical barrier methods, and pharmacological treatments have shown some benefits in case reports. The objective of this article is to review the prevalence, diagnostic criteria, etiology, historical and physical examination findings, pathological features, and current treatment methods. Onychotillomania remains a clinical challenge to dermatologists, pediatricians, internists, and psychiatrists in practice, as there are no evidence-based treatment methods.