The quake struck at 6:45 p.m. local time about 70 miles northwest of the capital of San Jose, according to the U.S. Geological Survey.
The epicenter was near the popular tourist town of Nicoya and occurred at a depth of about 40 miles.
There were no reports of significant damage or injuries from the quake, which was initially believed to have been an aftershock of a 7.6 magnitude temblor that struck over a month and a half earlier.
It was responsible for two deaths and scattered damage in parts of the country.
The September shaking was the most powerful Costa Rica had experienced since a 7.6 magnitude quake left 47 people dead in 1991.
A 6.1 magnitude earthquake in January 2009 killed 40.