An intriguing corrugation reversal in scanning tunneling microscopy (STM) images has been observed on several metal surfaces as well as on graphite. With a sudden change of tip condition, under the same tunneling conditions, the STM image can switch from positive (atoms being protrusions) to negative (atoms being depressions) and vice versa. In both cases, the absolute values of corrugation amplitude can be one order of magnitude greater than what is expected from the electron charge density near the Fermi level. We explain this effect as a manifestation of tip electronic states. If m not-equal 0 states dominate the tip electronic states near the Fermi level, images with inverted atomic corrugation are expected. For an m = 0, l not-equal tip state, noninverted images with large corrugation amplitude are expected. The type of image (i.e., inverted or noninverted) is expected to be independent of the tip-sample distance. The absolute values and the distance dependence of corrugation amplitudes expected from the tip-state effect are in agreement with experimental observations. Alternative explanations are discussed in conjunction with experimental observations.