The detection of ESBL in AmpC producing species of Gram negative bacteria is problematic. The study aimed to compare efficacy of MDDST and AmpC & ESBL detection set discs for detection of ESBL or AmpC or both in Gram negative bacilli. Three hundred fifty Gram negative bacilli were isolated and screened for ESBL production by disc diffusion method. The 100 ESBL producing isolates represents 28.5 % and 18 % of them were suspected to be ESBL & AmpC co-producers by cefoxitin screening test. The 100 isolates were then subjected for: phenotypic disc confirmatory test, MDDST and AmpC & ESBL detection set discs. By phenotypic confirmatory test, 95 % were confirmed to be ESBL producers. The sensitivity of the MDDST and ESBL & AmpC detection set discs were 100 % and 90.5 % respectively. On the other hand, both had the same specificity. There is no statistically significant difference between set discs method and MDDST in detection of ESBL & AmpC co-production. The most effective antimicrobial agents for ESBL producers were carbapenems. The study concluded that, MDDST provides a simple, cost-effective method for ESBL testing in clinical microbiology laboratories. The MDDST is more accurate, sensitive and cost effective than set discs method for ESBL confirmation.