This study analyses the source characteristics of voiced and voiceless nasals in Mizo, a Tibeto-Burman language spoken in North-East India. Mizo is one of the few languages that has voiced and voiceless nasals in its phoneme inventory. This analysis is motivated by the interaction between breathiness and nasality reported in a number of speech perception studies using synthetic stimuli. However, there are no studies examining this interaction in vowels after voiced and voiceless nasals. Existing research has also documented the interaction between breathy phonation and vowel height. The current study is an acoustic analysis of breathiness in high and low vowels following voiced and voiceless nasals in Mizo. The acoustic parameter measures are: H1H2 ratio, spectral balance (SB), strength of excitation (SoE), and waveform peak factor (WPF). The values obtained for all the four acoustic measures suggest that vowels following voiceless nasals exhibit stronger acoustic characteristics associated with breathy phonation than vowels following voiced nasals. In addition, the degree of acoustic breathiness is affected by vowel height. © 2018 International Speech Communication Association. All rights reserved.