Resistance to a wide variety of common antimicrobials has made the proliferation of extended spectrum beta lactamases (ESBLs) producing organisms a serious global health concern that has complicated treatment strategies. These bacteria have spread rapidly and have become a serious threat to human health worldwide. It is a great challenge for clinicians to treat bacteria harbouring these enzymes. So, the present study was undertaken to detect and characterize ESBLs in Escherichia coli and Klebsiella species by different methods, as well as to identify the possible risk factors for their development. Confirmed variants of Escherichia coli and Klebsiella species isolated from 439 patients that were admitted in various units of UMTH Maiduguri were screened for ESBL using CLSI breakpoints. Suspected ESBLs producers were subjected to confirmation using double disk synergy method. All confirmed ESBL positive isolates also had their MIC determined using Etest strips of cefotaxime and cefotaxime + amoxicillin-clavulanic acid. Detection of ESBL genes was further done by multiplex PCR. Out of the 439 isolates screened; the result shows 147 (33.5%) were ESBL producers but only 121(23.6%) were confirmed by the double disk synergy method. The prevalence of ESBL amongst the organisms were; 41/172 (23.8%) for Escherichia coli and 80/267 /(30.0%) for Klebsiella species. Based on PCR analysis, the various percentage genotypes of the ESBL producers were 44(36.4%) for SHV gene followed by 38(31.4%) for TEM gene and the lowest of 33(27.3%) for CTX-M gene. There was significant association between the acquisition of ESBLs and the following parameters based on chi-square test; Level of education (X2=22.034, P=0.005), place of residence (X2=7.619, P=0.022), ward of admission (X2 = 1.065, P = 0.000), number of days on admission (X2 = 76.367, P = 0.000), past medical history (X2 = 45.512, P = 0.000), use of medical device (X2 = 56.052, P = 0.000) and prior antibiotic usage (X2 = 54.564, P = 0.000). The predictors for acquisition of ESBL in the ward of admission, were admission in intensive care unit (OR = 25.692, 95% CI = 7.125-100.5777) and admission in special care baby unit (OR = 15.666, 95% CI = 3.724-49.125). Number of days on admission ≥ 25 days (OR = 36.07, 95% CI = 25.0-78.1) was also a predictor of ESBL acquisition. Past history of diabetes mellitus (OR = 1.831, 95% CI = 1.685-17.351) was found to be the predictor in the category of past medical history. However, for patients that used medical devices; the use of urethral catheter (OR = 61.8, 95% CI = 32.6-78.2) was the predictor of ESBL acquisition. The use of third generation cephalosporins in less than 4 weeks of admission (OR = 3.608, 95% CI = 3.326-33.146) was also significantly associated with ESBL acquisition. ESBLs are present among species of Escherichia coli and Klebsiella species in Maiduguri, Borno State and this calls for government and all stakeholders’ intervention in this area of healthcare setting. Clinical laboratories should employ methods for rapid detection of these ESBL isolates as recommended by CLSI. As these strains became resistant to available antibiotics and they pass the i gene to other clinical strains. Irrational use of third generation cephalosporins must be discouraged so as to reduce the prevalence of ESBLs. Antibiotic stewardship program should be established in all tertiary health centres of Nigeria.