Although much research has emphasised the effect of professional learning communities (PLCs) on teachers' collaboration, feedback provision, job satisfaction, and self-efficacy, few studies have focused on South Korea's unique context of government-led top-down policies to encourage PLCs. Using large-scale data representing all regions and sectors in Korea in the Programme of International Student Assessment (PISA) 2018, this study addressed the latent means differences in factors of teacher collaboration, feedback provision, job satisfaction, and self-efficacy between groups of teachers that had and had not participated in a PLC. All of the factors investigated were found to be higher among teachers that had participated in PLCs. Theoretical and policy implications are discussed.