Parental behaviour in sows begins with prepartum nest-building behaviour, which mainly consists of rooting, pawing, and foraging, to achieve a structure for farrowing and to nurse and protect the offspring. A hormonal background is linked to the onset and cessation of nest-building behaviour. The ambient farrowing environment that can adequately address the needs for nest-building behaviour thus plays an important role in good parental behaviour of the sows during and after farrowing. In addition to these environmental factors, here we also discuss other well-known intrinsic factors, such as heredity, parental experience, and litter size, affecting parental behaviour of the sows for successful farrowing and lactating performance.