The present research provides an acoustic description of vowel quality and quantity in Zilfaawi Arabic (ZA). The vowel duration and the first (F1) and second (F2) formants were measured. Acoustic analysis of the ZA vowels /i/, /i:/, /a/, /a:/, /u/, /u:/, /e:/, /o:/ was performed using eight monosyllabic CVC words. Ten native speakers of ZA each read the carrier phrase five times, producing a total of 400 tokens. This study also examines whether these aspects differ between men and women. The results revealed that the phonemic vowel inventory of this Saudi dialect comprises three short and five long vowels. The phonetic quality and duration of short and long vowels in ZA exhibited notable temporal differences, with speakers exhibiting long vowels of approximately twice the duration of short vowels. Close proximity was detected between adjacent vowel pairs /i/–/e:/ and /u/–/o:/ among women, with no statistically significant differences observed in their F1 values. In addition, the vowels produced by men displayed more retraction and height than those produced by women. Overall, the data indicated no significant difference in vowel duration between men and women.