This research aims to describe the qualities of the Acehnese oral monophthong vowels produced by the female and male speakers in Idi Rayeuk, East Aceh, who speak the North Aceh dialect in East Aceh. This research intends to fill in the research gap by also investigating the male speakers and further comparing the vowel production of both groups of speakers. This research was conducted with method of purposive sampling to select five female and five male speakers for the participants of this study. The data of the monophthongs quality were obtained through recorded words elicitation with the speakers. The researcher recorded the speakers to elicit the target words from the word list that contain the monophthong vowels. Based on the average values of the formants and t-tests, the results show that the vowel qualities between female and male speakers have significant differences. The vowel space of the female speakers is lower and more fronted while the vowel space of the male speakers is higher and more back. The comparison between both of the subjects agrees to the theory that female and male speakers produce sounds especially, monophthong vowels differently. Keywords: Acehnese, Oral Monophthongs, Vowel Formants, East Aceh