A method for outputting a 3D image and a display apparatus using the same are provided. The method for outputting a 3D image includes generating a left eye image and a right eye image using an input image, decreasing resolution of the left eye image and the right eye image by a predetermined positive number of times and outputting the left eye image and the right eye image by increasing an output frequency by the positive number of times. Accordingly, a 60 Hz timing controller used for a general display apparatus may be used and thus, a flickering effect and a cross-talk effect may be prevented.