In pig production, the relationships between welfare and the housing system are assuming increasing importance. The European Food Safety Authority (EFSA, 2005) has recently collected the results of several studies on the effects that different kinds of floor and different space allowances have on the health, performance and behaviour of pigs into a scientific report. The aim of this study was to evaluate for heavy pigs, the possible relationships between the kind of floor and the physiological and behavioural responses during pre-slaughter handling. Seventy-five crossbreed Duroc x (Landrace x Large White) heavy pigs (average hot carcass weight 134.6 kg), mostly castrated males, were examined. All animals were supplied by one farm; 37 were reared in 3 boxes with a solid floor and 38 were reared in 3 boxes with a full slatted floor. The space allowances ranged from 0.97 m² to 1.15 m² for the former group and from 0.70 m² to 0.89 m² for the latter group. All subjects were delivered to the slaughterhouse in one consignment using a three-deck truck. All passageways had solid floors. At the end of the journey, which lasted 44 min, and after a rest of 9 min in the truck, the pigs were unloaded and kept in the resting pens, with solid floors, maintaining the division of the boxes from the farm. After 30 min of lairage the pigs were stunned by electronarcosis. The behavioural events were recorded at loading and unloading, in the upper deck of the truck and in the resting pens. During loading and unloading the number of reversals, balks, falls, slips, jumps, bites, evacuations and vocalizations were recorded for each group of pigs. From the observations made during the journey and during the lairage, the frequency of pigs standing, sitting and lying down were calculated. At the exsanguination, blood samples were collected for the determination of plasmatic content of cortisol, lactate and creatine kinase. The frequency of behavioural events and positions were evaluated by a ÷² test (Fisher exact test) while the plasma blood analysis data, previously normalized by a log transformation, were processed using ANOVA by the GLM procedure of SAS (1996). At loading, the pigs reared on the slatted floor were more difficult to drive along the passageway leading to the vehicle, as demonstrated by the reversals and balks, which reached a total of 77 % of the observed events. These difficulties could be due to a low tendency to move in the farm boxes, as is common for pigs reared on slatted floors (EFSA, 2005), and to the novelty of the kind of flooring encountered to reach the vehicle. Instead, the pigs reared on the solid floor did not show any difficulties in running quickly along the passageway. During transport, the pigs from the boxes with slatted floors lay down before the end of the journey while pigs reared on solid floors showed this behaviour only when the vehicle was stopped at the slaughterhouse and in the lairage pens. Overall, the different kind of floor encountered during pre-slaughter handling increased the psychological stress in the pigs reared on slatted floors, as suggested by the higher level of cortisol. Nevertheless, the condition experienced did not lead to physical stress, as demonstrated by the similar values of lactate and creatine kinase between the two groups of pigs.