BACKGROUND: Prelacteal feeding (PLF) is a recognised challenge to optimal breastfeeding but remains common in Indonesia. Meanwhile, PLF-related epidemiological research is limited, particularly in this setting. This study examines the prevalence and determinants of overall PLF as well as common PLF types (formula, other milk, and honey) in Indonesia. METHODS: Data from 6127 mothers whose last child was ≤23-month-old were drawn from the 2017 Indonesia Demographic and Health Survey. Multivariable modified Poisson regression was used to measure the prevalence ratio (PR) for selected PLF risk factors. PLF was defined as anything to drink other than breast milk within three days after birth, before breastmilk flows. Additional analyses were performed on mothers who gave formula, other milk, and honey. RESULTS: About 45% babies in Indonesia received PLF with formula being the most frequent (25%), followed by other milk (14%), plain water (5%), and honey (3%). Factors associated with higher prevalence of any PLF were higher wealth quintiles in rural area (PR 1.07; 95% CI 1.03-1.11 per increase in quintile), baby perceived to be small at birth (PR 1.23; 95% CI 1.12-1.35), caesarean deliveries at either public (PR 1.27; 95% CI 1.13-1.44) or private facilities (PR 1.15; 95% CI 1.01-1.31), and not having immediate skin-to-skin contact after birth (PR 1.32; 95% CI 1.23-1.42). PLF was less prevalent among mothers who gave birth to second/subsequent child (PR 0.82; 95% CI 0.76-0.88) and who had an antenatal card (PR 0.89; 95% CI 0.80-0.99). These patterns did not apply uniformly across all PLF types. For example, honey was more common among home births than deliveries at health facilities, but formula and other milk were more common among caesarean deliveries. CONCLUSIONS: Mapping risk factors for PLF, especially by types, could help to design more targeted interventions to reduce PLF and improve breastfeeding practices in Indonesia.