The company sold 446,768 vehicles in the quarter, down from the 498,425 it sold a year earlier. Industry watcher Edmunds had estimated a 7.1% decline for the quarter.
"Our dealers have once again stepped up as pillars of the community as they have continued to provide critical support to our customers on the road," Fiat Chrysler's U.S. head of sales, Jeff Kommor, said in a statement.
"Many have taken extraordinary steps ranging from enhanced sanitizing protocols for their showrooms to the offer of home delivery and other concierge services to keep consumers safe."
This is the first glimpse investors are getting of just how much the coronavirus pandemic has affected the U.S. auto industry.
The company's Ram pickup-truck line was a bright spot in the quarter, increasing sales 7% to 128,805 vehicles. Overall, the Ram brand rose 3% to 140,486 vehicles.
Chrysler's Pacifica minivan saw a 5% increase in sales to 24,525 vehicles sold in the quarter. Jeep's Gladiator reported sales of 15,259 vehicles, its third consecutive quarter of at least 15,000 vehicles sold.
Overall, Fiat's Jeep brand saw a 14% decline in sales, while its Chrysler brand saw a 5% decline, Dodge fell 20% and Fiat dropped 49% in the first quarter.
Fiat Chrysler shares at last check dropped 4% to $6.90.