The reaction kinetics between acetic acid and Ag2+ in nitric acid medium is studied by spectrophotometry. The effects of concentrations of acetic acid (HAc), H+, NO3, and temperature on the reaction are investigated. The rate equation has been determined to be –dc(Ag2+)/dt = kc(Ag2+)c(HAc)c−1(H+), where k = (610 ± 15) (mol/L)−1 min−1 with an activation energy of about (48. 8 ± 3.5) kJ mol−1 when the reaction temperature is 25°C and the ionic strength is 4.0 mol L−1. The reduction rate of Ag2+ increases with the increase in HAc concentration and/or temperature and the decrease in HNO3 concentration. However, the effect of NO3 concentrations within 0.5–2.5 mol L−1 on the reaction rate is negligible. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: 47–51, 2013