Abstract: A new process for preparing oxalyl- and oxamyl-hydrazides which comprises contacting oxamide or diacetyloxamide with the corresponding hydrazine derivative of formulaR.sub.1 R.sub.2 N--NHR.sub.3wherein R.sub.1 represents a hydrogen atom or an optionally substituted alkyl, cycloalkyl, aryl, or aryl-alkyl group, R.sub.2 is a hydrogen atom or an optionally substituted alkyl group, or R.sub.1 and R.sub.2 taken together with the adjacent nitrogen atom represent a saturated heterocyclic ring, and R.sub.3 is a hydrogen atom or an optionally substituted alkyl group.