TOPMODEL is a widely used, physically based distributed rainfall-runoff model developed in the 1970s that has been used to model multiple watersheds from the Latin American sphere. However, to the best of our knowledge, it has not been applied in Peruvian watersheds. This contribution reports (1) the adequation of the particle swarm optimisation (PSO) for automatic calibration of TOPMODEL, and (2) the application of TOPMODEL to the Chillón and Cañete watersheds, Perú. The following metrics were obtained in the validation stage: Nash-Sutcliffe = 0.85 and Kling-Gupta = 0.87 (Cañete); and Nash-Sutcliffe = 0.79 and Kling-Gupta = 0.84 (Chillón). Under the light of these results, we believe that (1) PSO represents a reliable calibration method for TOPMODEL, which currently relies in the generalised likelihood uncertainty estimation (GLUE) methodology to that end, and (2) TOPMODEL successfully modelled the hydrologic processes at that study catchments at both daily and monthly basis.