In Precision Agriculture, the use of sensors provides faster data collection on plant, soil, and climate, allowing collecting larger sample sets with better information quality. The objective of this study was the development of a system for plant height measurement in order to mapping of sugar cane crop, so that regions with plant growth variation and grow failures could be identified and used for crop yield forecasting and management purposes. For georeferencing of the plant height measurement, it was developed a control and data acquisition system, that communicates through ASCII commands via radio frequency, using ZigBee protocol, and a PIC (Peripheral Interface Controller) board, which controls the ultrasound sensors. Also, the system communicates with a DGPS using the RS-232 interface emulated on the computer's USB “port”, synchronizing the height and location data. The experiment was performed 105 days after planting, using two ultrasound transducers, placed on distinct rows. The measurement system was assembled on a vehicle, which moved at an average speed of 5.7 m s-1, in a total area of 25 ha. The mapping of the plant height allowed the visualization of the local plant height variation. Thus, the use of the ultrasound sensors system for plant height measurement proved agile and practical, enabling the localization and identification of areas with reduced grows, for further management intervention.