A process for the continuous dyeing of textile material containing or consisting of synthetic fibers from organic solvents, which comprises impregnating the said textile materials with an organic dyebath containing at least one dyestuff of the formulaR.sub.2 O -- A.sub.1 -- N = N -- Y -- N -- A.sub.2 -- OR.sub.1in which A.sub.1 and A.sub.2 each represent, independently of each other, phenylene, lower alkyl-phenylene, lower alkoxy-phenylene, chlorophenylene, bromophenylene or naphthylene, Y represents phenylene, lower alkyl-phenylene, lower alkoxy-phenylene, di(lower alkyl)-phenylene, di(lower alkoxy)-phenylene, lower alkyl-lower alkoxy-phenylene, chlorophenylene, bromophenylene, biphenylene, di(lower alkyl)-biphenylene, di(lower alkoxy)-bi-phenylene, di(chloro)-biphenylene or di(bromo)-biphenylene, R.sub.1 represents a straight chain or branched alkylcarbonyl of at most 18 carbon atoms, benzoyl, lower alkyl-benzoyl, chlorobenzoyl or bromobenzoyl, and R.sub.2 represents a straight chain or branched alkylcarbonyl of at most 18 carbon atoms, benzoyl, lower alkyl-benzoyl, chlorobenzoyl, bromobenzoyl or lower alkyl ##EQU1## (of 2 to 4 carbon atoms, and an organic solvent and subsequently fixing the dyestuffs by a heat treatment.