The birth of a first child is a significant milestone for a woman life as it starts the challenging duties of motherhood. The objective of this study is to investigate the determinants of the age of women at first birth in Bangladesh by using quantile regression model. This research collected data from Bangladesh Demographic and Health Survey (BDHS) conducted in 2017-18. The final dataset of this study consists of 16,711 ever-married women whose aged 15–49 years. Result shows women's current age, education level, employment status, age at first sex (years), mass media exposure, wealth index and partner’s higher education have positive effect on the age of women at first birth. Conversely, husband’s current age, rural area, outside of the Dhaka division, current contraceptive user and female household head have negative effect. The study findings will help government and policymaker to take the necessary steps for increasing the women’s age at first birth.