Over the last decade, increasing attention has been given to understanding girls' menstrual hygiene management (MHM) experiences in school. However, little has been done to understand girls' MHM experiences in other contexts, such as the home environment. The purpose of this study was to explore the knowledge, attitudes, and practices of MHM and menstrual related experiences among rural Cambodians, with an expanded scope to include both the home and school environments, and five participant perspectives. Our study was conducted in eight rural secondary schools and eight rural villages from two Cambodian provinces, Banteay Meanchey and Kratie. Our target participants included girls (14+ years, post-menarche; n=120), mothers (n=88), fathers (n=15), teachers (n=37; 54.1% female), and boys (14+ years; n=59), for a total of 346 participants. Qualitative and quantitative data were collected using structured interviews (n=165), structured focus groups (SFGs) (24 SFGs: n=180), and observational latrine surveys (n=8). Qualitative analysis employed inductive approaches derived from Grounded Theory. Based on our findings, although girls expressed feeling capable of managing their menses each month, fear, shyness, and discomfort (FSD) associated with their menstrual experience was a major theme. As such, emergent categories from girls’ responses and other participant groups revealed three primary determinants of FSD: (1) relational impacts on FSD, regarding girls’ social experiences during menstruation; (2) knowledge-related impacts on FSD, indicating areas of knowledge that influenced MHM and FSD; and (3) managerial impacts on FSD, dealing with the material and WASH resources tha twere most pragmatic for MHM and influential on FSD. A fourth theme considered the impact of FSD on girls’ behavior. Quantitative and qualitative analysis showed that FSD had a significant impact on girls’ confidence, relationships, and decision-making regarding MHM. Evidence and recommendations from this study support the tailoring of programs and interventions to target overt social, educational, and environmental challenges and underlying factors that contribute to girls’ FSD, in order to meet the traditionally unserved MHM needs of women and girls.