In accordance with the law, citizens of all countries except the United States require a visa to visit Equatorial Guinea. Visas are obtained through one of the Equatorial Guinea diplomatic missions.
Visa exemption
Citizens of the United States can visit Equatorial Guinea without a visa. Citizens of other countries require a visa for all purposes including transit. Also, holders of diplomatic, official or service passports issued to nationals of Brazil, Cuba, China and Morocco do not require a visa for Equatorial Guinea.
References
Visa policy of Equatorial Guinea Wikipedia(Text) CC BY-SA