In countries with universal access to early childhood education and care (ECEC), child participation is high across a range of socioeconomic groups. However, ECEC quality is often varying, and many children spend much time in ECEC settings that are not necessarily high quality. In this observational study, we therefore examined the relationship between observed ECEC quality and children’s cognitive development at age three years in Norway – a country that provides universal access to ECEC from age one. The sample comprised 800 children, enrolled in 83 ECEC centers, who were assessed in verbal and non-verbal cognitive ability. ECEC quality was measured with the Infant/Toddler Environment Rating Scale (ITERS-R), and cognitive outcomes were measured with the Naming Vocabulary and Picture Similarities subtests of the British Ability Scales III (BAS III). The results showed that children’s cognitive development at age three was not associated with ECEC quality; irrespective of socioeconomic background.