X-radiography is a simple, rapid and non-destructive method for analysing the morphology of embryos in dry, mature seeds of Arabidopsis thaliana. In wild type seeds, the cotyledons, hypocotyl and radicle tip can be readily distinguished. In seeds of the mutant types knolle, keule, and the double mutant keulelgnom, aberrations in embryo morphology can be visualized. X-radiography may therefore be useful in the isolation of embryo mutants from Arabidopsis seed samples.