The effect of temperature during solvent annealing on the microdomain orientation of block copolymer ultrathin films was investigated using symmetric polystyrene-block-poly(methyl methacrylate) diblock copolymers. When acetone solvent annealing was performed at low temperatures, 2 degrees C, 38% of samples exhibited a pattern of cylinders perpendicular to the substrate, while 62% of the samples exhibited a mixture of cylinders orientated parallel and perpendicular to the substrate. In the case of acetone solvent annealing at room temperature, only 6% of samples exhibited a pattern with cylinders perpendicular to the substrate, while 73% of the samples exhibited a mixture of cylinders orientated parallel and perpendicular to the substrate. We discuss how the morphology is affected by temperature during solvent annealing. The low-temperature method was used to pattern cylinders perpendicular to the substrate using PS-b-PMMA copolymers with molecular weight ranging from 52 000 g/mol per block to 160 000 g/mol per block.