Abstract: This study evaluates the feasibility of using artificial neural networks (ANNs) methodology for estimating the groundwater level in some piezometers implanted in complex aquifer of Northwestern Iran. This aquifer is the more complex and has high water level in urban area. Spatiotemporal groundwater level simulation in a multilayer aquifer is regarded as a difficult subject in hydrogeology due to complexity and different aquifer materials. In present research the performance of different neural networks in a groundwater level forecasting is examined in order to identify an optimal ANN architecture that can simulate selected piezometers water levels and provide acceptable predictions up to 24 months ahead. Six different types of network architectures and training algorithms are investigated and compared in terms of model prediction efficiency and accuracy. The different experiment results show that accurate predictions can be achieved with a standard feedforward neural network trained with the Levenberg-Marquardt algorithm. Obtained structure and spatial regression relations of the ANN parameters (weights and biases) are used for spatiotemporal model presenting. It was found in this study that the ANNs provide the most accurate predictions when an optimum number of spatial and temporal inputs were included into the network and that the network with lower lag consistently produced better performance.