Statistics for Islam in Nicaragua are not readily available, but according to Fahmi Hassan, President of the Asociación Cultural Nicaragüense-Islámica  the Muslim population is near 500, mostly Arabs who immigrated to Nicaragua from the Palestinian territories and Lebanon, in addition to a growing number of indigenous converts. Recently the first mosque was constructed in the country on a parcel of land measuring three thousand meters in the San Juan district with a capacity for nearly one thousand people. And now there is also a new Islamic Center whos name is "Centro Cultural Islamico Nicaraguense" run by shiite Muslims in the country and their main goal is the spread of Islamic Teaching 

Source : http://en.wikipedia.org/wiki/Islam_in_Nicaragua