Etching properties of INCONEL718 with various degrees of fatigue damage have been investigated. The etching properties have been found to be sensitive to low-cycle fatigue damage given to the meterial. Low-cycle fatigue damage was simulated using load-controlled uniaxial fatigue tests at 600°C and also at room temperature, and samples with various degrees of fatigue damage were prepared. A chemical etching technique was utilized to detect fatigue damage, and it was found that the etching method preferentially etches persistent slip bands (PSBs) in the fatigue-damaged materials. The density of slip bands increased with increased fatigue life fraction and showed an unique correlation with a usage factor N/Nf. In conclusion, an applicability of the etching technique to fatigue damage evaluation has been suggested.