Applied Engineering in Agriculture 2002, Vol. 18(3): 367–372This study compared ultrasonic and laser measurements of citrus canopy volume with manual measurement methods. Fifteen trees with different canopy heights and volumes were used. Manual and ultrasonic measurements provided dimensions for computing the canopy volume whereas laser measurements gave information that could be used to compute a ‘laser canopy volume index.’ Ultrasonic and laser methods agreed with manual methods (R2 > 0.85, RMSE < 2.15 m3). Laser showed better prediction of canopy volume than the ultrasonic system because of the higher resolution. Ultrasonic or laser sensors can be used for automatic mapping and quantification of the canopy volumes of citrus trees.