The electron-induced chemistry of one monolayer (1 ML) of biacetyl (CH3COCOCH3) on Ag(111) has been studied using temperature programmed desorption (TPD), x-ray photoelectron spectroscopy, and Auger electron spectroscopy. Monolayer biacetyl has a sharp saturable parent peak at 180 K, with a tail toward higher temperatures that is attributed to defect sites. No thermal decomposition occurs, confirming that Ag(lll) is inert with respect to the breaking of C-C, C=O, and C-H bonds. Nonthermal excitation pathways by which the surface chemistry of biacetyl may be directed were explored by irradiating 1 ML of biacetyl with 50 eV electrons. During irradiation, CO, CH3, ketene (H2O=C=O), and C2H6 desorb. After irradiation, the parent TPD peak area drops with little change in position or shape. The initial total cross section for electron-induced decomposition of biacetyl is 8.0+/-0.2X10(-17) cm(+2). As products accumulate, this drops to 4.0+/-0.2X10(-17) cm(+2). The cross section has a threshold around 8 eV and rises smoothly with increasing energy. The ionization of biacetyl is proposed as the initiation step.