Across all five boroughs, 34 of the 50 businesses asked had seen a decline in business since April.
Of those surveyed, 19 said the reduction in business ranged from 10% to 50%. The average fall was 30%.
11 bars or restaurants noted little to no change, and three of them said business has been up since the ban.
Alex von Bidder, the manager at the Four Seasons bar, said: "My clients that enjoy a good bottle of wine and a cigar or perhaps a cigarette just aren't staying around long enough to do that anymore."