All visitors, except nationals of the Economic Community of West African States, need visas. Costs and processes vary by nationality and point of issue, and depending on who you ask.
According to the Guinea-Bissau's Permanent Mission to the United Nations office in New York City, visas are not issued upon arrival at the airport in Bissau. However, we know of several travellers who were issued single-entry visas at the airport with little problem for €85. The only caveat is, because of the uncertainty and if there are issues, it might not be worth the risk, especially if arriving in the early morning on a Royal Air Maroc flight.
Travellers report it's possible to get a visa upon arrival at the airstrip in Bubaque for those flying on a small plane from Cap Skirring or Dakar in Senegal.
The UN office in New York City issues 30-day single-entry visas for US$100; two passport photos are required and the process generally takes three to five days.
Guinea-Bissau's embassies and consulates elsewhere (in Europe, there are embassies in Berlin, Brussels, Madrid, Paris and Lisbon) reportedly can do the same, though the price and time varies (eg it's US$73 for a single-entry visa in Madrid). At the embassy in Dakar, it's reportedly CFA45,000 and an average wait of two days for a single-entry visa. At the embassy in Banjul, Gambia, costs vary depending on how quickly you want it processed (it's double to have it processed in three days versus eight). In Praia, the capital of Cape Verde, a single-entry visa reportedly takes a week and costs US$52.
There is an official government-sponsored website (www.rgb-visa.com) that purports to process visa requests electronically for US$66 (single entry) and US$77 (multiple entry) prior to arrival. Its responsiveness and effectiveness is uneven, to say the least. Even with an email confirmation, you might have a long wait upon arriving at the airport in Bissau.
Single- or multiple-entry visas are available from most sources.
Coming from Senegal, Guinea-Bissau single-entry visas can be attained quickly and with little fuss at the Guinea-Bissau consulate in Ziguinchor for CFA20,000. Bring at least one passport photos.
Single-entry visas for Guinea at the much-less-travelled southern route from Quebo to the border crossing at Contabane cost around CFA12,500. At the embassy in Bissau, they can be issued on the spot for around CFA30,000.
Extensions are easy to obtain at Serviço de Estrangeiros. For virtually all nationalities, 45-day visa extensions cost around CFA4000 and are ready the same day if you apply early.
Live flora and fauna can't be exported out of the country.