Novel tetrazolinone derivatives of formula (I) wherein R represents a group (a), R?3 and R4¿ each independently represents a hydrogen atom, alkyl, haloalkyl, cycloalkyl, aralkyl or phenyl, R5 represents phenyl, aralkyl, phenoxyalkyl or phenylthioalkyl, R?1 and R2¿ each independently represents alkyl, haloalkyl, cycloalkyl, alkenyl, alkinyl, aralkyl or phenyl, or R?1 and R2¿ may form, together with the nitrogen atom to which they are bonded, a heterocyclic group, a process and intermediates for their preparation and their use as selective herbicides.