The purpose of the study is to detect Metallobetalatamase (MBL) producing GNB (Gram Negative Bacilli) isolated from various clinical samples received in the Department of Microbiology, Kilpauk Medical College & Hospital, Chennai. All the isolates that were resistant to ceftazidime collected and MBL production was demonstrated by combined disc test with EDTA and double disc synergy test. Among the GNB’s isolated from clinical samples, 41 % showed resistance to ceftazidime. These GNB’s which were resistant to ceftazidme were tested for MBL production, 29% were found to be MBL producers. These 29% of MBL producers showed resistance to commonly used antibiotics. Thus, MBL producers are seen not only among non fermenters like pseudomonas aeruginosa but also produced by Enterobacteriaceae causing problems in treating patients with infections.