Reducing post-harvest losses in the grain production system are of great interest to Brazilian agricultural production. Truck transport is commonly used world wide for the distribution of goods for trade. In Brazil, truck transportation is usually the most economical way to distribute goods in places where inexpensive or natural means of transport alternatives are not available. Truck transport plays a significant role in moving raw materials and processed products from the agricultural production. This study aimed to evaluate the post-harvest loss in transportation in soybean in the state of Piaui. The route of trucks loaded with soybean was analyzed from two regions. The trucks were weighted when leaving the farm and again weighted when arriving at the processing plant. Results indicate that there was a difference in weight between the farm and final destination indicating possible losses during the road transport.