This disclosure describes novel alkyl 3-[6-(aryl)-3-pyridazinyl]-carbazates useful as hypotensive agents in mammals. SP CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of our copending application Ser. No. 692,254, filed June 3, 1976 now abandoned, which in turn is a continuation-in-part of our abandoned application Ser. No. 552,024, filed Feb. 24, 1975 now abandoned.