On approaching slaughter weight it is common practice to weigh pigs and they are very often slap-marked prior to transport to the abattoir. Weighing involves handling and temporary isolation of the animal. Slap-marking involves hitting the animal, usually on the shoulder, with a series of needles covered in tattooing ink. Both weighing and slap-marking are potentially stressful. This study measured the behavioural and heart rate response of animals to these procedures as they occured on a commercialy run pig unit. These were compared to the responses of animals to weighing and an open-field test in an experimental procedure.