Common organisms which were isolated from patients attending the King Abdulaziz University Hospital in Jeddah were tested against antibiotics commonly used for their eradication. About 500 isolates of each bacterium were tested, showing a different resistance pattern from that obtained in Western countries. For example, methicillin resistance by staphylococci was different from that found in the United Kingdom, 100% of pneumococci were sensitive to penicillin and pseudomonas resistance to carbenicillin was only about 3%. S. typhi resistance of Chloramphenical was nil. This paper emphasizes the most appropriate antibiotic for each organism and the different pattern of bacterial resistance in Saudi Arabia as compared to that in Western countries.