Background and Objective: The risk of infection by microorganisms in blood, saliva and exudates from infected patients in dental and medical centers has always been a threat to the patients and the medical staff alike. We do not always have enough time to autoclave the instruments, so this has brought about the need to develop different ways to quickly disinfect the instruments. Furthermore, deconex (a trademark) is a famous detergent for disinfecting surfaces and equipment. Nanosilver due to its smaller particle size has greater contact surface and has many uses as new antibacterial agent. The purpose of this study was to compare the effect of nanosilver colloid particles and deconex P53 plus solution on Pseudomonas aeroginosa (ATCC 27853) and Staphylococcus aureus (ATCC29213).    Materials and Methods: To measure the effective antibacterial concentration of nanosilver and deconex 53 plus, the MIC and MBC measurement methods were used.  Results: The MIC and MIB concentration of nanosilver for Staphylococcus aureus was 10 ppm and for pseudomonas aeroginosa was 100 and 500 ppm respectively.  Conclusion: The nanosilver particles and deconex 53 plus has bactericidal effect on Staphylococcus aureus, so its MIC is equal to the MBC, but in the case of pseudomonas aeroginosa, the value of MBC for nanosilver and deconex were 5 and 20 times greater than their MIC respectively.