The common infective conditions encountered at King Khalid Teaching Hospital, Riyadh, Saudi Arabia were described. These data were collected mostly during a period of 8 years between 1981 to 1988. These infections included brucellosis, cholecystitis, conjunctivitis, enteric fever, gastroenteritis, infective endocarditis, meningitis, otitis media, pneumonia, septicaemia, sorethroat, treponemal infections, urethritis, urinary tract infections, and vaginitis. A scheme for empiric chemotherapy has been suggested for these infections based on the sensitivity results obtained mostly from the microbiology laboratory at Teaching Hospital, Riyadh. This scheme of empiric therapy is offered as a guide only. It does not cover all possibilities and is not intended as a rigid dogma. Empiric therapy has also been suggested for some other infective conditions where sufficient data were not available from the Teaching Hospital. Empiric therapy should be started after relevant specimens are collected. Culture and sensitivity tests are invaluable in the management of patients with infectious diseases. As soon as sensitivities of the infecting organisms' are known, treatment should be adjusted accordingly. In some cases, Gram-staining is valuable to guide the initial therapy (eg. meningitis, pneumonia, and urethritis). Finally, close liaison between physicians and clinical microbiologists is mandatory for successful therapy.