BACKGROUND AND OBJECTIVES: Routine use of antibiotics for infectious diarrhea in children is associated with the risk of increasing antibiotic resistance in developing countries. This work aimed to study the predominant extended spectrum beta-lactamase (ESBL) genes among bacteria pathogens implicated in acute childhood gastroenteritis in a tertiary hospital in Nigeria. MATERIALS AND METHODS: The stool samples of children diagnosed with acute gastroenteritis were collected. Isolation and identification of bacterial pathogens from the stool samples using standard microbiological and molecular sequencing methods. Pure cultures of the probable bacteria pathogens were subjected to antibiotics susceptibility profiling using the Kirby-Bauer Disk Diffusion Method and also screened for ESBL and AmpC using the Modified Double Disc Synergy Test. Primers for 5 different ESBL genes associated with beta-lactam antibiotic resistance were amplified and sequenced. RESULTS: Out of the 62 isolates, the highest number of organisms identified within the isolates were Bacillus sp at 38.7% (24) followed by Alcaligenes sp at 37% (23). Resistance to cefepime and ceftazidime were recorded at 50.8% (30) each. Ceftriaxone and cefotaxime were resisted in 47.4% (28) of the isolates. Out of 34 isolates resistant to all the cephalosporins used, 41.2% (14) were ESBL-producing, of which blaCTXM-1 and blaCTXM-2 were detected in 85.7%, while blaTEM was seen in 64.3%. CONCLUSIONS: blaCTXM and blaTEM may be the predominant ESBL genes haboured in the bacteria pathogens implicated in the yearly incidence of acute childhood gastroenteritis in Nigeria. This may be due to the widespread use of antibiotics in treating this disease.