Aim: Onychomycosis is a rare pathology in infants which constitutes 15.5% of onychodystrophies in children, especially those with Down syndrome and the immunocompromised. Dermosocpy is an innocuous examination allowing to guide the clinical diagnosis and to avoid invasive examinations. Presentation of Case: 5-month-old infant presents with thickening of the thumbnail of the left hand with xanthonychia evolving for 20 days without notion of trauma. On clinical examination, xantho-pachyonychia of the thumbnail of the left hand was noted reaching the latero-distal part with subungual hyperkeratosis and peronyxis. Dermoscopy showed yellowish chromonychia, longitudinal striae, subungual hyperkeratosis with jagged edges. The mycological direct examination and culture was in favor of a Candida albicans infection The patient was put on an antifungal cream with improvement after 3 months. Discussion: The rarity of onychomycosis in infants can be attributed to several factors such as the difference in the structure of the nail plate, less exposure to trauma and rapidity of nail regrowth. The average age is 8 months, the sex ratio at 0.98 and the preferential location is the fingernails. Clinically the nail involvement is of the disto-lateral type with subungual hyperkeratosis and peronyxis. Dermatoscopy is a quick tool showing chromonychia, longitudinal streaks, subungual hyperkeratosis producing a “ruined appearance”, distal onycholysis with jagged edges and linear hemorrhages. Infant onychomycosis is most often of candidal origin (C. albicans). Topical antifungals (ciclopirox) are preferred. Conclusion: This case is being reported to highlight the important role of dermoscopy in the diagnosis of onychomycosis and thus prevent unnecessary biopsies.