A detailed description is given of the reproductive tract of the sow as felt by rectal examination. Rectal examination was found to have a 94.3% accuracy in determining pregnancy when carried out between 30 and 60 days gestation. Rectal examination was also found to be a suitable method of detecting the onset of oestrus in the sow. The advantages of using rectal examination as a routine procedure to determine pregnancy in commercial sow herds are presented.