Animal welfare during the transport and slaughter of pigs is in the interests of consumers and producers. All procedures and human-animal interactions on the day of slaughter are potentially stressful for the pigs. Good handling practices—calm handling and a handling set to the individual needs of the pigs—and management of the animals provide the maximum animal welfare at slaughter, but only by avoiding or minimizing any further external stressors in addition to the transport and the slaughter itself. By conducting a systematic literature review, we wanted to find out which procedures and human-animal interactions were found by researchers to have an impact on welfare during pig transport and slaughter. Direct human-animal contact and the management of transport and slaughter procedures were identified as major influencing factors. As the animal welfare-sensitive areas of stunning, control of stunning, and bleeding are highly important, personnel should be trained regularly to ensure good practices and animal welfare. Deficient handling and procedures in the transport/slaughter processes can be critically scrutinized and corrected only when personnel are sufficiently educated. Knowledge of best handling practices is necessary to reflect on our own and other personnel’s behaviour and to maintain awareness of animal welfare. Animal suffering caused by humans is not acceptable.