OBJECTIVE:To assess the prevalence of menstrual hygiene management (MHM) knowledge and practices among adolescent schoolgirls in Indonesia, and assess factors associated with poor MHM and school absenteeism due to menstruation. METHODS:A cross-sectional survey enrolled a representative sample of urban and rural school-going girls aged 12-19 years in four provinces of Indonesia. A semi-structured, self-administered questionnaire obtained socio-demographic characteristics, knowledge, practices and attitudes related to menstruation, MHM and school absenteeism. School water, sanitation and hygiene (WASH) facilities were also assessed. Univariate weighted population prevalence was estimated and multivariable logit regression analyses applied to explore associations. RESULTS:A total of 1159 adolescent girls with a mean age of 15 years (SD = 1.8) participated. Most girls (90.8%, 95% confidence interval (95% CI) = 79.7-96.1) had reached menarche. Over half (64.1%, 95% CI = 49.9-76.2) reported poor MHM practices, and 11.1% (95% CI = 8.1-15.2) had missed one or more days of school during their most recent menstrual period. Poor MHM practices were associated with rural residence (Adjusted odds ratio (AOR) = 1.73, 95% CI = 1.13-2.64), province (various AOR), lower school grade (AOR = 1.69, 95% CI = 1.05-2.74) and low knowledge of menstruation (AOR = 3.49, 95% CI = 1.61-7.58). Absenteeism was associated with living in rural areas (AOR = 3.96, 95% CI = 3.02-5.18), province (various AOR), higher school grade (AOR = 3.02, 95% CI = 2.08-4.38), believing menstruation should be kept secret (AOR = 1.47, 95% CI = 1.03-2.11), experiencing serious menstrual pain (AOR = 1.68, 95% CI = 1.06-2.68) and showed mixed associations with school WASH facilities. CONCLUSIONS:High prevalence of poor MHM and considerable school absenteeism due to menstruation among Indonesian girls highlight the need for improved interventions that reach girls at a young age and address knowledge, shame and secrecy, acceptability of WASH infrastructure and menstrual pain management.