1-(naphthalen-2-yl)-2-(1H-pyrazol-1-yl) ethanone (MPPY) was synthesized. The structure was characterized by spectral analysis (1H-NMR, FTIR). The molar absorptivity of MPPY is high enough, similarly to acetonaphthone derivatives, to be used as an efficient type I photoinitiator. The influence of MPPY concentration and the addition of the co-initiator N-methyldiethanolamine (MDEA) on methyl methacrylate (MMA) polymerization were also investigated. Additionally, MPPY showed good antibacterialactivity against Escherichia coli and Staphylococcus aureus (diffusion method).