The incidence of antibiotic resistant extended-spectrum β-lactamase (ESBL)-producing bacteria in humans has markedly increased due to the indiscriminate use of antibiotics. This study examined the prevalence and antibiotic resistance patterns of ESBL-producing gram-negative bacteria obtained from clinical samples of patients at a tertiary hospital in Iloilo City, Philippines, concomitant to confounding variables including age, sex, and hospital status and admitting diagnosis, from April to June 2016. Of the 295 gram-negative bacterial isolates examined, 228 (77%) were presumptively found positive for ESBLs in the screening test while only 67 (23%) were confirmed as ESBL producers. The ESBL-producing bacteria were accordingly identified as Escherichia coli (46%) and Klebsiella pneumoniae (54%). Majority of ESBL-positive bacteria examined for antibiotic susceptibility test showed maximum sensitivity to carbapenems (imipenem, meropenem and ertapenem) and an aminoglycoside (amikacin), clearly indicating that these drugs could be effectively used for the treatment of ESBL-associated infections. Additionally, the high prevalence of ESBL-producing bacteria in clinical samples examined in the current study suggests that mandatory routine detection for ESBL should be regularly conducted to guide medical practitioners in formulating a dynamic policy guidelines on the rational use of antibiotics in hospitals.