In this paper, we are interested in iris biometric applications. More precisely, our contribution consists in designing both a pupil detection and a tracking procedure from video sequences acquired by low-cost webcams. The novelty of our approach relies on the fact that it is operational even with a minimal user cooperation and, under bad illuminations and acquisition conditions. A robust classification algorithm is designed to detect the pupil. Moreover, a pupil tracker based on the extended Kalman filter is applied in order to reduce the processing time. Experimental results are performed in order to evaluate the performances of the proposed detection and tracking system.