A self-drilling screw includes a shank and at least one thread. The shank includes a self-drilling portion, a head portion spaced from the self-drilling portion along a longitudinal axis, and a straight rod portion between the self-drilling portion and the head portion. The thread is spirally formed on the straight rod portion and includes a plurality of thread convolutions. Each thread convolution is provided with three to eight recesses spaced apart circumferentially, and a screw thread portion is formed between two adjacent recesses. The recess features a recess length circumferentially, and the screw thread portion features a screw thread length circumferentially. The screw thread length is 25% to 200% of the recess length. The self-drilling screw can be driven into articles to be fastened quickly without loss of binding forces between the self-drilling screw and the articles.