Microbial load of borehole water sample from Irrua and surrounding settlements was determined using standard microbiological methods. Susceptibility of the bacteria isolated to commercial antibiotics was also assessed. Results showed that total viable count ranged from 0.12 x 10² to 2.8x10²cfu/ml, while the total coliform count ranged from 4 to 16 MPN/100ml. Microbial count differed significantly among the areas of study. Predominant bacterial isolate include Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Lactobacillus species. The antibiogram carried out using the disc diffusion technique showed that most of the isolated bacteria were highly resistant to the tested antibiotics but were susceptible to a few antibiotics tested. The zone of inhibition of the gram positive isolates ranges from 8mm to 13mm, while the zone of inhibition of gram negative isolates ranges from 7mm to 12mm. The antibiotics with the highest susceptibility on the Gram positive isolates (B. cereus and Lactobacillus sp) were Pefloxacin, Ciprofloxacin and Septrin. Ciprofloxacin had the best activity on the two Gram negative isolates. The organisms obtained in this study are of public healthimportance, hence water samples require proper treatment before domestic use to eliminate bacterial involved in waterborne disease outbreaks.