Dangerous Drug Diversion Control Act of 1984 - Amends the Controlled Substances Act to allow the Attorney General to place an uncontrolled substance under temporary controls which provide for registration, recordkeeping, and criminal penalties. Authorizes the Attorney General to exempt certain compounds, mixtures or preparations from control. Provides for administrative changes in the registration of practitioners. Authorizes the Attorney General to make grants to State and local governments to assist them in controlling the diversion of controlled substances from legitimate channels. Provides for forfeiture of controlled substances possessed in violation of such Act.

Amends the Controlled Substances Import and Export Act to revise the importation requirements for narcotic and nonnarcotic substances. Makes changes in the registration requirements for importers and exporters of controlled substances. Allows the Attorney General to deny, revoke, or suspend a registration taking into consideration the public interest and international obligations.

Makes it unlawful to export controlled substances from the United States without the required proof that the export does not violate the law of the importing country.

Allows the Attorney General to authorize the importation of certain narcotic raw materials (opium, poppy straw, and coca leaves) necessary for medical or scientific purposes.