This study addresses teachers' practices of collaborating with parents on upbringing. It was inspired by the understanding that teachers contribute to upbringing in their day-to-day interaction with students and by the renewed interest in the upbringing-related goals of education in Western societies. The study aimed to learn more about the topic and collaboration practices that emerge from primary school teachers' narratives about collaborating with parents on upbringing. Teachers' practices of collaborating with parents on upbringing are under-researched, and the topic is not often taught in teacher education. Narratives of 34 teachers about practices of collaborating with parents on upbringing were collected in the Netherlands through the method of letter writing. The narratives show a variety of topics: the interwovenness of care, upbringing, and teaching in teachers' practices and views; and a school-focused approach to upbringing goals in education. In this research, three characteristics of teachers' collaboration practices on upbringing were distinguished: (1) teacher--parent equality; (2) a reflective attitude; and (3) commitment to parents. The results show that practices of "collaboration," "limited collaboration," and "no collaboration" can be distinguished. Consequences for teacher education are discussed.