The study examined the effect of teachers' formal, nonformal and informal learning experiences on their promotion to middle leadership roles in schools during their first ten years of work. Analyses were based on data from two cohorts of Israeli teachers who completed their pre-service programs in the years 2005-2006 (N = 4208). They were followed for ten years until 2015. Results showed a differential effect. The effect of formal learning was the most influential factor of teachers' promotion to leadership roles throughout the years. Informal learning was the second influential factor. Nonformal learning had the lowest effect.