An ultrasonic flow meter is a complex devices that, for its development, involves different disciplinary fields such as the electronics, the mechanics, the acoustics and the material science. For this purpose, it has been developed both a simulator of an ultrasonic flow meter and an ultrasonic flow meter in order to validate the simulator. The simulation take into account of the transducer property, of the fluid dynamics and of the acoustic propagation inside the measurement conduct of flow meter. In this work, the results of the simulations used to describe the performance of an ultrasonic flow meter for liquid is presented. Furthermore the validation of the adopted models has been performed comparing the simulation results with the collected data.