The increased usage of antibiotics has induced microorganisms to acquire resistance factors which have become a burning predicament. As a result, there is an urgent need to find an alternative to chemotherapeutic drugs in disease treatment particularly those of plant origin which are easily available and have considerably fewer side effects. In this study, in-vitro antibacterial activity of ethanol extract of Zingiber officinale (ginger) was investigated using the agar diffusion method on some clinical isolates (Klebsiella pneumoniae, Streptococcus mutans, Escherichia coli, Staphylococcus aureus, and Shigella dysenteriae). Phytochemical analysis of the extract was carried out using gas chromatography-mass spectrometry (GC-MS). Data obtained were subjected to one-way analysis of variance (ANOVA) procedure using SPSS (version 21) computer software. The extract of Zingiber officinale was active against all bacterial isolates with varying zones of inhibition that ranged from 12mm-24mm. Zingiber officinale extract had the highest zone of inhibition (24mm) at the concentration of 100mg/ml on E. coli followed by S. aureus (21mm) and K. pneumonia (18mm). Results of the phytochemical analysis of the Z. officinale extract showed the presence of some identified bioactive compounds (Geranyl acetate, α-Pirene, Camphene, Eucalyptol, Camphore, Terpin-4-ol, Citronellol, Geraniol, 2-Heptanol, Terpinolene, hexamethyl- etc.) that have antimicrobial properties. Therefore, results obtained from this study showed that the ethanol extract of Zingiber officinale possesses antibacterial properties against the clinical isolates tested which invariably make it a potential candidate for the treatment of some bacterial infections.