Costa Rica's first female president pledged to reach out to citizens and not favor special interest groups during her swearing-in ceremony.
Laura Chinchilla, 50, took the oath of office Saturday. She was elected in February with 47 percent of the vote.
Chinchilla replaces former Nobel laureate and her mentor Oscar Arias, who praised Costa Ricans for recognizing that a woman is capable of leading the country.
In her inaugural address, the new president vowed to move the country toward a more innovating, intelligent and entrepreneurial path.
Chinchilla, who will serve a four-year term, holds a master's degree in public administration from Georgetown University and served as vice president between 2006 and 2008.