A new field strength prediction model for the mobile phone environment is presented. The model is based on the principles of popular feedforward neural networks. Utilizing a new artificial neural network model some important disadvantages of both deterministic and empirical models can be overcome. In order to build the model, extensive field strength measurements were carried out inside two different buildings. The analysis of the model has shown that the proposed model is fast, accurate (on the order of the focal mean measurements uncertainty) and reliable.