Yellow Fever — Mandatory
A yellow fever vaccination certificate is required for entry into French Guiana. You must present it at the airport or border crossing. Get vaccinated at least 10 days before arrival. This is non-negotiable and strictly enforced.
Malaria
Malaria is present in French Guiana, but the risk varies significantly by location. In Cayenne, Kourou, Sinnamary, and the main coastal towns, risk is low to negligible. Risk is significant in the interior — particularly along the rivers bordering Brazil (Camopi, Saint-Georges, Regina) and in Maroon communities along the Maroni. If you're visiting Saul or traveling by river into the interior, take appropriate antimalarial medication (consult your doctor before departure) and use DEET-based insect repellent and long sleeves/trousers at dawn and dusk.
Dengue and Zika
Both are present year-round. There is no vaccine or specific treatment for dengue; prevention is the same as for malaria — repellent and covering exposed skin. Pregnant women or those planning pregnancy should consult a doctor about Zika risk before traveling.
Insects
Beyond malaria risk, the insects in the jungle are intense. Sandflies (no-see-ums) are tiny, vicious, and active near rivers and at dusk. Good repellent, a mosquito net, and closed footwear in the evening are essential.
Medical Care
Cayenne has the main hospital (Centre Hospitalier Andrée Rosemon) with reasonable facilities. Kourou and Saint-Laurent-du-Maroni have smaller clinics. Medical care meets French standards in the main towns. In the interior, there is essentially no medical infrastructure — evacuation to Cayenne is necessary for anything serious. Travel insurance with medical evacuation coverage is important if you're going off the coast.
Pharmacies
Well-stocked pharmacies operate throughout the main towns, often with French-trained pharmacists who can advise on common ailments and antimalarial medications.