A rack-and-pinion steering apparatus comprises pinion teeth formed according to proper tooth specifications in other aspects under a larger pressure angle, thereby stably offering smooth and comfortable steering feeling over a long time. The module (m), number of teeth (z), tooth depth (h) and helix angle (β) of the pinion teeth (4) are set within the following ranges, under a pressure angle (α) set within a range of 24° to 30° and a given stroke ratio. module (m): 1.8 to 2.0 number of teeth (z): 7 to 13 tooth depth (h): 2 m to 2.5 m helix angle (β): 35° or smaller