Pairs of patients were evaluated for microbiological cross-contamination after radiographic examination. In 30 of these pairs of patients there was the possibility of transference of S pyogenes, S aureus, or D pneumoniae. Such transference was observed in 23 (77%) of these 30 pairs of patients. The vectors for such transfer include the hands of the X-ray technician and the radiographic equipment. Further, it was found that each of these organisms would survive for at least 48 hours after being placed on an X-ray tube. Since interpatient microbiological cross-contamination can occur after routine radiographic examination, in some cases, disinfection of the radiographic equipment is indicated.