A method for producing nitrobenzene is disclosed which comprises forming a dispersion comprising benzene-containing droplets or particles dispersed in a mixture of concentrated nitric acid and concentrated sulfuric acid, wherein said particles have a mean diameter less than one micron, and subjecting the dispersion to reaction conditions comprising a pressure in the range of about 203 kPa (2 atm) to about 6080 kPa (60 atm) and a temperature in the range of about 20.degree. C. to about 230.degree. C., whereby at least a portion of said benzene is nitrated to form nitrobenzene. A system for carrying out the method is also disclosed.