Introduction: School-based and community-based sexuality education has not shown a significant impact on the sexual and reproductive health (SRH) outcome of Sri Lankan adolescents. Parents as the primary educators of adolescents would be a better source of providing individualized sexuality education to their children. Objective: To assess the existing pattern of mother-daughter communication of sexual and reproductive health (SRH) matters among Sinhala adolescent girls aged 14-19 years in Sri Lanka. Methods: A descriptive-cross sectional study was conducted among a sample of 810 Sinhala adolescent girls, using a pre-tested, self-administered questionnaire. Descriptive statistics related to mother-daughter communication of SRH matters were presented using frequencies and percentages. Bivariate analysis was performed to assess the association of selected socio-demographic factors with mother-daughter SRH communication while Binary logistic analysis was performed to assess the independent association of selected demographic factors with mother-daughter SRH communication. Results: The majority of the respondents (67.1%, n=540) were positive about discussing SRH matters with their mothers. For 78.2% (n=632) mother was the most preferred source of SRH information. Issues related to menstruation (88.4%, n=701), keeping body limits (94%, n=718), and preventing sexual violence (72.6%, n=574), were among the common topics discussed between mothers and daughters. Cultural barriers (46.8%, n=379),and fear of parental perception (56.3%, n=456), were the main barriers to discussing SRH topics with mothers. Adolescent girls’ age, religion, status of schooling, and family income level were significantly associated with mother-daughter SRH communication. Conclusions and recommendations: Adolescent girls identified the mothers as a good source of SRH information. Parents' contribution as a primary source of SRH information to adolescent girls when planning adolescent sexual health interventions needs to be considered.