Proceptive and receptive aspects of behaviour were studied during the oestrus cycle of the female pig. These aspects were studied in a T-maze with one or two stimulus compartments that did or did not contain a teaser boar. Receptive behaviour was observed during several consecutive days and was quantified in front of the boar by using the back pressure test (BPT). Three aspects of proceptive behaviour, i.e. the tendency to 'search the boar', 'stay close to the boar' and 'to present' in front of the boar peaked in the middle of the receptive period, and in most gilts on the day preceding the last receptive day (Experiment 1). In contrast, preference for a particular boar, another aspects of proceptive behaviour, was only expressed during the days preceding and following the receptive period (Experiment 2). The results are discussed in terms of the possible functional implications of proceptive and receptive behaviour in relation to fertilization.