Background: Menarche is the main milestone for adolescent girls marking the onset of their puberty. Adequate menstrual preparation is essential for a healthy menstrual life. This study aims to explore the menstrual preparation and related experiences of adolescent girls living in long-term Palestinian refugee camps in the West Bank and Jordan. Methods: 39 in-depth interviews and 23 focus group discussions were conducted with 15-18 years girls between March and September 2018. Results: The findings highlighted inadequate menstrual preparation of adolescent girls, which focused mainly on practical aspects and hygenic practices and neglected biological, emotional, or psychological aspects. Menstrual preparation was mainly the responsibility of mothers and to a lower extent, teachers, and usually hindered by a general culture of taboo and secrecy, what the girls referred to as "aib عيب". Appropriate information usually started after menarche, leaving girls with limited knowledge on what to expect or how to deal with menstruation. Girls' own reports indicated that many had their first periods with almost no information, resulting in a dramatic reaction with fear and anxiety as dominant feelings. Conclusions: This study highlights the need to address menstrual preparation for adolescents. Preparation needs to be initiated early, before menarche, with adequate information, practices, and emotional and psychological support to help girls expect and respect what is happening to their bodies. This can be achieved by schools acknowledging the need for adequate information as a first step, followed by a collaborative atmosphere between households, schools, and health services.