Simple SummaryAn extensive body of literature has been produced on the effects of transport-related factors on the welfare of adult pigs, while less attention has been paid to weaned piglets. Understanding how to safely transport weaned piglets is very important as they present their own set of challenges and risks. Despite this gap in the scientific literature produced to date, transporting piglets immediately after weaning is a common practice and every year millions of weaned piglets are transported on long journeys to reach the growth-finishing farms. The combination of the stress of weaning and transport can lead to negative effects on the health and welfare of piglets. The review will provide an in-depth discussion of the main factors that affect the welfare of weaned piglets during transport and will highlight the need for more research on key factors affecting the welfare of piglets during transport aimed at providing scientific evidence to the existing recommendations and/or regulations.AbstractThe purpose of this review is to present the best available scientific knowledge on key effects of pre-transport and transport factors influencing the response of piglets to transport stress and post-transport recovery. To date, research on piglet transportation particularly focused on the effects of season (i.e., heat and cold stress), vehicle design features (ventilation type and deck/compartment location), space allowance and transport duration, and piglet genetics. More specifically, in this review the effect of transport duration has been dealt with through its impact on death rate, behaviour and physiological response, and feeling of hunger and thirst. Based on the available literature, clear conclusions can be drawn on the vulnerability of piglets to heat stress during transport. Both short and long transportation have an effect on piglet welfare, with effects being biased by the genetic background, ambient conditions and vehicle design. Further studies investigating the impact of factors such as vehicle design, truck stocking density and environment, piglet genetic background, and weaning age are needed.