The purpose of this study was to evaluate the microbiological conditions of the egg crater mattress in hospital use to identify the presence of Staphylococcus aureus and its methicillin-resistance phenotype (MRSA). Petrifilm plates were used to collect the microbiological data from the mattresses, in pre-established positions. A total 180 plates were collected in 15 mattresses, 139 (72.2%) of which were positive for Staphylococcus aureus. Of the positive plates, 77 (55.4%) were collected before and 62 (44.6%) after washing the mattresses. There was a significant reduction (p=0.023) in Colony Forming Units (CFU); however, regarding the resistance profile, 8 (53.3%) mattresses with MRSA were identified. Results show the risk of these mattresses acting as a secondary deposit in the infection chain, especially regarding the presence of MRSA.