Uncinariasis or ancylostomiasis, a.k.a. tropical anemia, is an intestinal parasitosis of great importance worldwide. Hookworms are parasitic nematodes transmitted by skin contact with contaminated soils. One of the most important consequences of massive infection by these parasites is chronic intestinal bleeding, which leads to reduced hemoglobin. In unusual cases the resulting anemia may be severe. With the purpose of discussing the importance and morbidity of this disease, a case is presented of a male 23-year-old patient from a tropical area in Peru who was admitted for an emergency hemoglobin value of 2.3 mg/dL, altered mental status and a history of rectal bleeding. During diagnostic examination, colonoscopy revealed multiple parasites with bleeding areas and erosive colitis, whereas parasitological analysis found eggs of Ancylostoma/Necator spp 2+. Symptoms improved after treatment with albendazole. Uncinariasis should always be suspected in the process of diagnosis of patients with chronic anemia both in Peru and in tropical areas worldwide.