The extended-spectrum beta-lactamases (ESBL) are derived from TEM-or SHV-enzymes. They mediate resistance to broad-spectrum beta-lactams and can cause infectious outbreaks in hospitals. Rapid recognition and diagnosis are important for the clinician to prescribe more effective treatment. In the present study, a group of 52 probable ESBL-producing Klebsiella pneumoniae and Escherichia coli having a suspected resistant antibiogram phenotype were included. The E-test ESBL screen and the double disk test were performed for these isolates for detection of ESBL-producing strains, as compared with the conventional agar dilution method. The agreement between the E-test ESBL screen or the double disk test and the conventional agar dilution method was good and the degree of agreement were 86.5% and 92.3% respectively. The results showed that both the E-test ESBL screen and the double disk test were useful and convenient for detection of ESBLs.