All diplomatic missions in Nicaragua are located in Managua [1], mostly along Carretera Masaya and Carretera Sur. The city of Chinandega [2] hosts consulates from El Salvador, Honduras, and Costa Rica, and the city of Rivas [3] has a consulate from Costa Rica.
Americans living or traveling in Nicaragua can register with the U.S. Embassy in Nicaragua (Kilometer 5.5, Carretera Sur, Managua, tel. 505/2252-7100, http://nicaragua.usembassy.gov [4]) at the main international travel page of the U.S. State Department (www.travel.state.gov [5]). Registering is not a legal requirement but is encouraged by the embassy so that they can send you updated travel and security advisories regarding Nicaragua.
These advisories—and the warden messages on the embassy website—are invariably on the conservative side, as far as risk assessment.
Other contacts: Information Resource Center (tel. 505/2252-7237) or American Citizens Services (ACS.Managua [at] state [dot] gov).
The Canadian Embassy in Managua [1] is actually an outpost of their main embassy in San José, Costa Rica [6]. The address in the Bolonia neighborhood is on Calle El Nogal, one block east from the Casa Nazareth (tel. 505/2268-0433 or 505/2268-3323, fax 505/2268-0437, mngua [at] international [dot] gc [dot] ca). For emergencies involving Canadian citizens, call the emergency consular service in Ottawa collect at 613/996-6885.
Costa Rica: half a block east of Estatua Montoya along Calle 27 de Mayo, tel. 505/2268-7460. There is also a consulate in Rivas [3] and Chinandega [2].
Cuba: Carretera Masaya from the third entrance to Las Colinas, two blocks east, 75 meters to the south, tel. 505/2276-2285.
El Salvador: Las Colinas, Ave. El Campo Pasaje Los Cerros no. 142, tel. 505/2276-0160.
Guatemala: Carretera Masaya Km 11, tel. 505/2279-9834.
Honduras: Carretera Masaya Km 12, 100 meters toward Cainsa, tel. 505/2279-8231.
Panamá: third entrance to Las Colinas, then two blocks east and 75 meters south, tel. 505/2276-0212.
Austria: from the Rotonda El Güegüense, one block north, tel. 505/2266-0171 or 505/2268-3756.
Belgium: Consulado de Bélica, Reparto El Carmen across from the Esso station, Calle 27 de Mayo, tel. 505/2228-2068.
Denmark: Plaza España one block west, two blocks north, half a block west, tel. 505/2268-0253.
Finland: Bolonia, one block north, 1.5 blocks west of the Hospital Militar, tel. 505/2266-3415.
France: Reparto El Carmen, 1.5 blocks west of the church, tel. 505/2222-6210.
Germany: 1.5 blocks north of the Rotonda El Güegüense, tel. 505/2266-3917.
Great Britain: Los Robles, from the old Sandy’s on Carretera Masaya, one block south, a half-block west, tel. 505/2278-0014 or 2278-0887.
Italy: one block north and half a block west of the Rotonda El Güegüense, tel. 505/2266-6486.
The Netherlands (Holland): Bolonia canal 2, half a block north, one block west, tel. 505/2266-4392.
Norway: one block west of Plaza España, tel. 505/2266-4199.
Russia: Las Colinas, Calle Vista Alegre No. 214, tel. 505/2276-0131.
Spain: Las Colinas Avenida Central No. 13, tel. 505/2276-0968.
Sweden: one block west, two blocks north, and half a block west of the Rotonda Plaza España, tel. 505/2266-8097.
Switzerland: Consulado de Suiza, one block west of the Las Palmas Clinic, tel. 505/2266-5719.
China: Planes de Altamira, from the Copa office 200 meters south across from the tennis courts, tel. 505/2267-4024.
Japan: Bolonia, from the Rotonda El Güegüense one block west, one block north, tel. 505/2266-1773.
Links:
[1] http://www.moon.com/destinations/nicaragua/managua
[2] http://www.moon.com/destinations/nicaragua/northwest-coast/chinandega
[3] http://www.moon.com/destinations/nicaragua/ometepe-and-rivas/rivas
[4] http://nicaragua.usembassy.gov
[5] http://www.travel.state.gov
[6] http://www.moon.com/destinations/costa-rica/san-jose