In scientific literature, early pubertal timing emerges as a risk factor of adolescents’ drinking, whereas alcohol-specific rules (the degree to which parents permit their children to consume alcohol in various situations) showed to protect against adolescents’ drinking. This study investigated whether alcohol-specific rules mediate and/or moderate the effect that early pubertal and psychosocial timing (personal, relational, socio-institutional) has on adolescents’ alcohol use. Mediation and moderation models were tested conducting ordinal logistic structural equation modeling in a cross-sectional sample of 1,893 Dutch adolescents (49% males), aged 13–15 years. Findings showed that early pubertal, relational and socio-institutional timers were at greater risk to initiate alcohol use and for heavy episodic drinking. Alcohol-specific rules more often mediated, rather than moderated, the effect of early timing on alcohol use. Alcohol-specific rules are mostly relaxed when adolescents mature, rather than reinforced, indicating that parents partly facilitate adolescents’ drinking.