The in vitro effect of three herbicides commonly used in wheat or corn plant protection programs in Romania on mycelial growth of entomopathogenic Beauveria bassiana (BbTd1) were investigated. The formulations with Isoxaflutole 225 g/L + Thiencarbazone methyl 90 g/L + cyprosulfamide (safener) 150 g/L (Adengo), Nicosulfuron 40g/L (Nicogan) and dimethylamine salt 600g/L (Dicopur) were tested at three different concentrations (field recommendation- FR, half and twice the FR) both on solid and liquid media. On the solid media, the radial growth of the fungus was measured for 11 days. On the liquid media mycelial biomass was weighted after 7 days of incubation on a rotary shaker. Dicopur significantly inhibited the vegetative growth of B. bassiana BbTd1 in both culture media at tested concentrations. In liquid media, mycelial growth was stimulated by Adengo and Nicogan at different concentrations. No significant differences caused by Adengo and Nicogan compared to control of radial growth was detected. The results showed that Adengo and Nicogan could be used simultaneously with this entomopathogen in integrated control programs. Further in vivo studies are necessary to establish if Dicopur formulation can cause damage to field populations of entomopathogenic fungi.