Menstruation, despite being a normal occurrence, is still seen as unclean or dirty in Bangladeshi society, and is associated with a number of myths and practices that lead to negative health outcomes. A descriptive cross sectional study was conducted from December, 2020 to August, 2021. Data was collected from adolescent girls of age group (10-19) years in railway slum area of Khulna city. Sample size was 121 adolescent girls. More than half 55.4% respondents had moderate knowledge on menstruation and menstrual hygiene and 17.4% respondents had good knowledge on menstruation and menstrual hygiene. On the other hand, 71.1% respondents had poor practice about menstruation and menstrual hygiene and 10.7% respondents had good practice on menstrual hygiene The source of information regarding menstrual hygiene where the highest percentage carried out by friend is about 34.2%. Age had significant association (Pearson's chi-squared test was 0.000, where a degree of freedom was 33 and the probability was 74.27, which was P=<0.05) with the level of knowledge about menstruation and menstrual hygiene. Significant association showed between the level of knowledge and practice of adolescent about age, education religion, use of absorbent, disposal of absorbent, change of absorbent and washing process of absorbent (where P value was < 0.05). It can be concluded that risk factors for developing urinary tract infection due to poor menstrual hygiene can be reduced by providing proper health education among the adolescent.