This article presents a spectral analysis of the voiceless postalveolar fricative phoneme in Tajik. It reveals a spectral difference in the phonetic realization of the phoneme between two varieties of Tajik, namely, the standardized variety used in Dushanbe, Tajikistan, and Bukharan Tajik, a regional variety spoken in Uzbekistan. It also reveals effects of the speaker’s sex and the vocalic environment on the spectral center of gravity (CoG) of the fricative in question.