The objective of this paper is to review current knowledge concerning synthetic aperture radar applications to crops in Canada. Following a brief overview of studies during SURSAT (1978-1980) and RADARSAT (1981 and later) projects, several issues are considered. These include crop-classification accuracies achieved with SAR or SAR and VIR data at various sites, the importance of crop and soil parameters affecting SAR images, the procedures for digital SAR image analysis and the relationship between airborne SAR data and future satelliteSAR data. Finally, recent developments of new ground and airborne microwave instruments to be used in agricultural studies are described.