High isostatic pressure (HIP) and Dynamic high pressure (DHP) are emerging technologies recently highlighted as able to improve enzyme activities. Lysozyme is an enzyme with antibacterial activity that is susceptible to modifications by both the processes. This study evaluated the impact of HIP (at 300 and 400 MPa for 10 min at 20 ºC and 600 MPa/ 10 min/ 50 ºC) and DHP (at 40, 80 and 120 MPa at 20ºC) on the antimicrobial activity of the lysozyme against Escherichia coli ATCC 11229, Enterococcus faecalis ATCC 29212, Geobacillus stearothermophilus ATCC 10149 and a Bacillus cereus isolated in a dairy industry. The minimal inhibitory concentration (MIC) of lysozyme (native and processed at different conditions) was determined for each microorganism, using inoculums of ~ 103 CFU.ml-1. Results showed that MIC of unprocessed lysozyme was 0.1 mg.L-1 for G. stearothermophilus, 150 mg.L-1 for B. cereus and > 500 mg.L-1 for E. faecalis and E. coli. None of the evaluated process conditions made the lysozyme effective against E. faecalis and E. coli at concentrations up to 500 mg.L-1. On the other hand, lysozyme processed by HIP at 300 and 400 MPa was more effective than native one for inhibition of the growth of B. cereus and G. stearothermophilus, reducing the MIC from 150 for 50 mg.L-1 for B. cereus and from 0.1 for 0.05 for and G. stearothermophilus. DHP, on the contrary, did not improved the inhibitory performance of lysozyme and, for several conditions, it was required a higher concentration of processed lysozyme to guarantee microbial inhibition when compared with unprocessed one. Therefore, comparison between the results of HIP and HPH indicated that although both processes are capable of changing the muramidase activity, only HIP increased the antimicrobial activity of lysozyme.