OBJECTIVE to compare the degree of bacterial contamination of surgical instrument tables used in clean surgical procedures, either protected with plastic fields, sterilized with ethylene oxide, or disinfected with 70% alcohol and 1% iodine solutions. This is a randomized clinical trial in which samples were collected from the surfaces of surgical instrument tables before and after each procedure. Microbiological analysis was performed to identify microorganisms and their respective antimicrobial resistance. RESULTS Bacterial growth in the surgeries using sterilized plastic was 5.71% before and 28.6% after surgery and, 2.9% and 45.7% respectively in surgeries using disinfection with 70% alcohol and 1% iodine solutions; no statistical difference was found between the methods. CONCLUSION both methods present similar protection, however, 70% alcohol and 1% iodine do not generate solid waste.