En el período comprendido entre junio del 2003 y junio del 2005 se trataron con hidroxiurea 45 pacientes con anemia drepanocítica; 16 niños y 29 adultos, al menos con una de las manifestaciones siguientes: más de 3 crisis vasooclusivas (CVO) dolorosas al año en los 3 años previos al estudio, uno o más episodios de síndrome torácico agudo (STA) al año en los 2 años previos al estudio, o accidente vascular encefálico (AVE) en el año anterior. La hidroxiurea se administró en dosis de 15mg/kg/día. El número de CVO dolorosas, STA, AVE, ingresos y transfusiones disminuyó significativamente (pFrom June 2003 to June 2005, 45 patients with drepanocytic anemia, 16 children and 29 adults, with at least one of the following manifestations were treated with hydroxyurea: more than 3 painful vasoocclusive crises (VOC) at a year and 3 years before the study, one or more episodes of acute thoracic syndrome (ATS) at a year and 2 years previous to the study, or vascular encephalic accident (VEA) in the previous year. Hydroxyurea was administered at doses of 15mg/kg/day. The number of painful VOC, ATS, VEA, admissions and transfusions decreased significantly (p<0.001). There was not either reduction of the hematological parameters or increase of creatinin or alanine aminotransferase. An important rise of fetal hemoglobin values (p<0.008) was reported. There were no toxic manifestations and the fulfilment was good. It was proved in this paper that it is not necessary to take the maximum tolerated dose of hydroxyurea to improve the clinical picture in drepanocytic anemia. Two of its advantages are its lower toxicity and the less expensive treatment. This would make possible that a greater amount of children in those countries with scarce resources may benefit from the treatment.