Vaccine and health: Visas and vaccines: All travelers must present the International Certificate of Vaccination against yellow fever, if they are coming from countries defined by PAHO/WHO as having active transmission and at this time:

• Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Panama, Paraguay, Peru, Venezuela and from the African Continent, all countries, Tanzania, Sao Tome and Principe and Somalia.

No visa required.

Documents to present:

1. Valid passport with a minimum of six (6) months.
2. Vaccination card against yellow fever, in case of coming from a country at risk (according to WHO list), which has no expiration date, provided that the vaccination card is in good condition.
3. Economic solvency.
4. At the entrance to the country, to cancel tourism tariffs, according to the General Law of Tourism (tourist card of 10 dollars Attention: To have the $10.00 in cash, since the migratory authorities do not accept any other form of payment). 
5. Complete the "Entry Request" form. This requirement is for all foreigners entering Nicaragua by air, sea or land. The form must be filled out and sent to the following e-mail address: solicitudes@migob.gob.ni . It is recommended to send the application with as much time as possible. Once the request is resolved, the corresponding Border Post(s) and the applicant(s) will be notified.
6. When visitors present themselves at the Border Post, their entry is authorized in a more agile, orderly and secure manner.

More details here.

Additional

• Formularuio, aquí.

More information here.