Artificial neural networks (ANN) are a novel approximation method for complex systems especially useful when the well-known statistical methods are not efficient. The multilayer perceptrons have been mainly used for hydrological forecasting over the last years. However, the connectionist theory and language are not much known to the hydrologist communauty. This paper aims to make up this gap. The ANN architectures and learning rules are presented to allow the best choice of their application. Stochastic methods and the neural network approach are compared in terms of methodology steps in the context of hydrological forecasting. Recent applications in hydrology are documented and discussed in the conclusion.Key words: artificial neural networks, hydrological forecasting, stochastic models, multilayer perceptrons.