Objective: to evaluate the effects of Colistin in the treaments of nosocomial infections caused by pandrug resistant (PDR) Gram-negative bacteria. Methods: 16 patients with nosocomial infections caused by PDR Gramnegative bacteria at the medical ICU of Viet-Tiep hospital from 4/2012 to 3/2013 were treated with intravenous Colistin. Results: the mortality rate was 37.5
9 cases caused by Acinetobacter (56,3 percent), 13 cases hospitalised acquired pneumonia (81,2 percent)
5 patients were treated Colistin combine imipenem and doxycyclin are successfully 100 percent, only 1 case increased renal failure. Conclusions: Colistin treatment in nosocomial infections caused. by PDR Gramnegative bacteria has the mortality rate 37,5 percent. Combine Colistin with imipenem and doxycyclin for a 100 percent success rate. PDR Klebsiella and Pseudomonas respond to treatment Colistin better than Acinetobacter. The side effects of treatment Colistin was rarely.