A venetian blind for a skylight in which there are at least two sets of slat supports each in the form of ladders, each set of ladder support comprising two or more ladders, these ladders each having depending longitudinally spaced double cross-rungs at the same location with one group of venetian blind slats being mounted on one of the double cross-rungs of one of the ladders of each set and other slats being mounted on the other double cross-rungs. In use, in an open position of the blind, the two or more slats at the same location are adjacent one another.