Abstract: Described are stable liquid formulations of nitrogen mustards. The nitrogen mustard includes mechlorethamine, cyclophosphamide, ifosfamide, melphalan, chlorambucil, uramustine, thiotepa and combinations thereof. The formulation includes a non-aqueous liquid having at least a first solvent either individually or in combination with one or more additional solvents. The formulation further includes an antioxidant, an organic acid, and a source of chloride ions.