To stay a month, only passport and return ticket is necessary.

Driver's license: You need to have a local license valid for three months (you must pay around 54EC$, i.e. 22 Euros) that you'll take at immigration office of Hewanorra and Vigia airports, at police department or in car rental agencies. You must be older than 25 and to have 2 years old license.

Airport tax: To leave Santa Lucia you have to pay 53EC$ (22 Euros)

No vaccine mandatory