The storm wrecked the port of Puerto Cabezas in northern Nicaragua, tearing the roofs off homes and shelters and damaging a church with winds in excess of 250kph.
A young girl was among the four who died in Puerto Cabeza.
Felix followed Hurricane Dean, another Category 5 storm - the most powerful type - which struck last month, killing 27 people in the Caribbean and Mexico.
Felix had provoked fears throughout Central America of a repeat of Hurricane Mitch, which killed about 10,000 people across the region in 1998 in floods and mudslides.
It was the first time on record that two Atlantic hurricanes made landfall as Category 5 storms in the same season, and the fourth time since records began in 1851 that more than one Category 5 had formed in a year.
Second hurricane strikes
In the Pacific Ocean a second hurricane, Henriette, lashed Mexico's Los Cabos resort on the Baja California peninsula with winds and rain, after killing a foreign tourist on its approach.
Despite growing consensus that global warming may spawn stronger tropical cyclones, weather experts believe it is too soon to blame climate change for the back-to-back hurricanes.
|As Felix passed over, many towns found |
themselves under water [AFP]
The area where Felix made landfall is sparsely populated and dotted with lagoons and marshes.
The storm threatened many Honduran and Guatemalan villages further inland that are perched on hillsides and vulnerable to mudslides.
Felix weakened to a tropical storm as it ploughed through northern Nicaragua on its way towards the Honduran capital of Tegucigalpa but was still dangerous.
"We expect it to cause rivers to overflow, mudslides and damage to roads, so we are calling on towns to take preventive measures and evacuate the populations in the most risky areas," said Jose Ramon Salinas, a Honduran civil protection officer.
About 70,000 Hondurans were evacuated to shelters, but some 15,000 people were unable to find transport and were forced to ride out the storm in their homes.
In Tegucigalpa, residents rushed to buy provisions in a busy supermarket, which in 1998 ended up half under water when a nearby river overflowed from the rains dumped by Mitch.