This study examines the perceptual motivation behind dissimilation. Consistent with previous arguments suggesting that dissimilation originates from perception rather than production (Coetzee, 2005; Kiparsky, 2003; Scheer, 2013), we hypothesized that an oral stop with short of voice onset time (VOT) would be recognized as non-aspirated more often when it is followed by an aspirated stop with a long VOT. This hypothesis was tested through a perception experiment in which 32 Korean listeners made judgments on the first consonant of C1VC2V words manipulated with C1 VOT and C2 types. The results revealed that aspirated-based C1 was recognized as aspirated or tense depending on the duration of VOT, while lenis-based C1 was consistently recognized as lenis. The dissimilatory effect of aspirated C2 was confirmed as anticipated, and furthermore, tense C2 increased the ratio of tense responses more than aspirated C2. These results provide evidence of a perceptual bias against recurrent aspirated stops, which may play a role in activating a dissimilatory rule or constraint in a language. The assimilatory effect of tense C2 is in consistent with findings indicating that word-initial tensification is facilitated by the following tense stop in Korean (Kang & Oh, 2016; H. Kim, 2016).