A complete sample of 120 northern galaxies of angular diameters a > 2 arcmin and apparent axial ratio a/b > 7 (Karachentsev et al., 1992) is considered. It is found that at least 50-60% of spiral galaxies exhibit warps in outer parts of optical disks with typical amplitude 4°-5°. The observed frequency of warped galaxies does not show significant dependence on morphological type: spirals of all types demonstrate warped disks. Disks of more massive, large and luminous galaxies are, probably, somewhat less warped.