This paper presents the technological improvement on sugar cane yield monitor. The system designed employs load cells as an instrument for weighing billets, set up on the side conveyor of the harvester before the sugar cane billets are dropped into a field transport wagon. This data, along with the information gathered by GPS installed on the harvester, enabled the elaboration of a digital yield map using GIS. In order to improve the yield monitor a re-design of the first prototype was accomplished. To evaluate the accuracy of the yield data obtained, field tests were carried out during 2006/2007-harvest season. The weight attained showed a mean error of 8.7 %. A yield map of 28.1 ha area plot was drawn. The yield monitor was tested during six months without presenting any fault, evidencing that the technological alterations performed on the equipment made it more robust and reliable.