Short-acting neuroleptic drugs are used to prevent adverse effects of stress in wildlife. We compared the effect of aceproma-zine and haloperidol in Iberian ibex (Capra pyrenaica) captured with box-traps. We captured 23 male Iberian ibex at the National Game Reserve of Ports de Tortosa i Beseit, northeastern Spain, March 2003–June 2005. Seven animals received 0.1 mg/kg of acepromazine maleate, eight received 0.33 mg/kg of haloperidol and eight animals acted as controls. Clinical, hematologic, and serum biochemical parameters were analyzed. Both treatments decreased rectal temperature, white blood cells, lymphocytes, and concentrations of creatinine, creatine kinase, and lactate dehydrogenase. Acepromazine also decreased red blood cells, packed cell volume, hemoglobin concentration, neutrophils, and concentrations of glucose and cholesterol. Haloperidol also decreased heart rate and concentrations of urea and potassium. Our results demonstrate the suitability of using acepromazine and haloperidol in capture operations to reduce stress and prevent its adverse effects.