A yield monitor is a device used to measure harvested crop weight per unit area for a specific location within a field.  The device documents yield variability in harvested fields and ultimately can be used to create a geographical-referenced yield map. Yield maps can be used to identify low yielding areas where poor soil fertility, disease, or pests may adversely affect yield.  Management practices can then be adjusted to correct these issues, resulting in an increase in yields and production efficiency. Although yield monitors are well established in small grain crops, a consistent, functional yield monitor has yet to be developed for the sugarcane chopper harvester. The objective of this research was to develop a yield monitoring system that could be used in the Louisiana sugarcane industry. A yield monitor was constructed for a billet-type sugarcane harvester that uses two laser distance sensors mounted above the loading elevator to measure the height and length of the billet piles per slat. By using this method, a volume to mass relationship can be established for the weight flow of sugarcane through the combine. Testing of the system indicated that the cumulative billet pile length had the best relationship to harvested weight and exhibited a linear relationship with coefficients of determinations ranging from 0.93 and 0.97. Estimated yields matched actual yields with a 0.99 slope and a coefficient of determination of 0.87. Yields were predicted to be within 7.3 metric tons per hectare of actual values. Material height did not perform as well as material length and had a relationship to harvested weight with coefficients of determination ranging from 0.66 to 0.93. Estimated yields matched actual yields with a coefficient of determination of 0.46. The product of material height to material length also returned a power curve relationship to harvested weight with coefficients of determination ranging from 0.74 to 0.96. Yield comparisons exhibited a coefficient of determination of 0.74, which was better than the material height alone, but not as good as material length by itself. Statistical testing indicated that variances in material length were strongly correlated to material flow, but not to sugarcane variety, direction of cut, or day of testing. Sample analysis indicated that the monitor should be able to predict yields to within 2.2 metric tons per ha of actual values on 0.4 ha or larger precision farming blocks. The yield monitoring system developed in this research project is easily installed and would allow sugarcane farmers to produce yield maps that could be used to optimize their farming practices and potentially increase yields and profits.