A study was conducted in the intensive care unit at Fatmawati Hospital, Jakarta, concerning a factor influencing the inappropriate use of antibiotics, proven by the resistance against a certain antibiotic, however this antibiotic was used for therapy. Cases in the control group were resistant cases against an antibiotic and therefore were given another antibiotic, against which the patients were sensitive. A total of 34 cases were selected as research subjects, whereas 41 cases were included in the control group. The factor influencing the use of antibiotics against which patient were resistant was “having a job of the patient” (odds ratio = 0,25 and 95 % CI 0,09 – 0,71). In comparison the group of patients with a job with the group without a job: the group with a job had a 75 % lower risk in using ineffective antibiotics.