The population of Nicaragua in 2011 was about 5,666,301 people. The chart below shows the steady population growth of Nicaragua over the past 50 or so years.
Comparing Nicaragua to other countries in the region, the populations of Costa Rica and Panama are smaller at 4,576,562 for Costa Rica and 3,460,462 for Panama in 2011. The population of Honduras, another neighbor of Nicaragua, is significantly larger at 8,143,564 people for 2011, which makes it almost 2.5 million people larger than Nicaragua.
Nicaragua Population Growth Rate
Even though the population of Nicaragua has been growing, the growth rate has been steadily declining and is now around a 1%. This is a significant change from the early 1990's when the population growth rate of the country was 5.8%. However, the population surge in the early nineties was largely due to a large influx of people migrating into the country after the anti-Sandinista political parties defeated the incumbant Sandinistas party which had been in power since 1979.
As you can see in the chart above, the driving force behind Nicaragua's population growth has been driven by the extremly high birth rate. The birth rate has been as high as almost 5% per year back in the early 1970's, but has steadily declined over the years and is now around 2% per year. The number of people migrating out of the country has consistently outpaced the number of people migrating into the country. This net migration out of the country has counterbalanced the historically high birth rate, however as the birth rate has declined the net migration out of the country has helped to lower the overall population growth.
In 2001 Nicaragua was the fourth largest country by population in Central America behind Guatemala at 13,824,463, Honduras at 8,143,564, and El Salvador at 6,071,774.Source Data: U.S. Census Data