A descriptive, cross-sectional, retrospective study of the drugs use, whose overall objective was to determine the characteristics of the use of Ciprofloxacin in hospitalized patients in of the Edgardo Rebagliati Martins National Hospital (ERMNH), during the year 2007, which used the methodology the defined daily dose for one hundred beds/day (DDD/100beds-day). It was made with computerized information of use of Ciprofloxacin. The data were drawn from the database hospitalary management system. Use of Ciprofloxacin in hospitalized patients in ERMNH - year 2007 was higher among female with 60.47% and in the age group of 60-69 years with 16.79%, and the 29.69% of this use was as clinical criteria and 73.31% according to the microbiological criteria. The most common diagnostic for which indicates the use of Ciprofloxacin were postoperative wound infections (26.67%) and urinary tract infecti...