We present a Monte Carlo study of the roughening transition on the vicinal Ag(115) surface. The simulations are performed within the framework of the terrace ledge kink (TLK) model. The values for the two energies that serve as input parameters in this model are taken from the scanning tunnelling microscopy experiments of Hoogeman et al. [Phys. Rev. B, 53 (1996) R13299]. From a quantitative analysis of the height correlation function measured from the simulated configurations we determine the roughening temperature TR=423±6K. This roughening temperature is close to the theoretical prediction of the TLK model and the experimentally obtained TR. We discuss the influence of periodic boundary conditions and show that finite-size effects on the value of TR are small.