Most people believe that it is highly probable that many animals are aware of both themselves and their surroundings. It may follow that a group of sows should not be reared as a homogenous mass because they are individuals each with their own distinguishable characteristics, or in other words each has a personality. It may also be the case that sows having different dispositions may be either more or less susceptible to certain environmental and psychological stressors and these in turn could affect reproductive performance. Hemsworth et al (1981) has found previously that on those farms where sows displayed a greater withdrawal response from a human investigator the number of piglets born per sow was significantly reduced. The purpose of the present experiment was to investigate the possibility that relationships may exist between the personality of multiparous sows, endocrine status and ultimately reproductive performances.