Simple SummaryTransport and lairage conditions can negatively affect pig welfare and carcass quality. The effects of transport and lairage conditions are not clear because some studies were focused on one or two main factors within a well-controlled environment, without considering the interaction of commercial conditions. Therefore, the aim of the study was to assess pig welfare at the slaughterhouse based on the presence of skin damage and to evaluate the effects of transport and lairage conditions. For research purposes, 4507 pigs were transported from one farm to one slaughterhouse. On the slaughter line, skin damage was separately scored per carcass part (shoulder, middle, and ham). The incidence of skin damage was most prevalent in the shoulder region of the pig carcass. Sex, wind velocity, regrouping, transport combination, transport compartment, lairage time, and ham angle affected the skin damage incidence. In conclusion, the incidence of skin damage is influenced by many factors and is an indicator of the level of welfare exercised during transport and slaughterhouse conditions.Transport and associated handling can have adverse effects on pig welfare. The transport of fattening pigs can cause economic losses by virtue of mortality, skin damage, and the general deterioration of meat quality. A total of 4507 fattening pigs were transported from a farm to a commercial slaughterhouse (distance 110 km) in 128 transports. Skin damage was visually assessed in the slaughter line in different parts of the carcass, i.e., shoulder, middle, and ham, using a 4-point scale. The incidence of skin damage was most prevalent (31%) in the shoulder region of the pig carcass. Sex, wind velocity, regrouping, transport combination, transport compartment, lairage time, and ham angle affected the skin damage incidence. In conclusion, scoring the incidence of skin damage is an indicator of the level of welfare exercised during transport and the slaughterhouse conditions. Furthermore, skin damage monitoring can be used to determine critical control points in the transport procedure. Given the importance from both a commercial and welfare perspective, it should be a powerful incentive to handle fattening pigs with care during the transport process and the lairage period.