In this work we present the head assembly and the gaze shifting capabilities of the bipedal humanoid robot Romeo. The purpose of the head system is to provide a reliable hardware platform for Human-Robot Interaction (HRI) applications, stereo vision based navigation or gazing experiments, either as stand-alone version or in synergy with the body movements. Towards this purpose, the number of joints, the angular range, speed and acceleration of the eyes and neck rotations should be should be in agreement with human psychophysics, i.e. reproducing realistic kinematics. We present a mechatronic system of the head and neck; accompanied by experimental results of head-fixed eye movements, solely head rotations, as well as eye-head cooperative motion for large angles of gaze shifting. We compare the values achieved by the prototype, with those of an average adult human.