The state’s 440 licensed casinos brought in $618m, ending a streak of three consecutive months of revenue topping $1bn.
Casinos were open for the first 17 days of the month. Governor Steve Sisolak ordered all non-essential businesses to close on 18 March.
Clark County revenue fell 38%, better than the Strip (46%) and Downtown Las Vegas (26%).
North Lake Tahoe suffered the steepest drop, as win declined by 65%.
Table, counter and card games accounted for $150m of earnings (down 56%) while slots brought in $467m, a 31% drop.
Sportsbooks reported a $1.5m win, down 95% from last March.
Of the $141m wagered on sports, $89m was placed on mobile apps, accounting for 63% of all handle.
Mobile sports wagers produced revenue of $3.8m with a 4.3% hold.
