To provide more insights into what motivates a diverse and skilled pool of candidates to enter the teaching profession, this chapter uses data from PISA 2006 and 2015, and analyses cross-country differences and trends over time in the characteristics of 15-year-old students who expect to work as teachers when they are 30 years old. This chapter also identifies factors that are associated with countries' ability to attract individuals with high skills and with an unconventional background (i.e. men and children of non-native parents) to the teaching profession. Factors that shape early career aspirations greatly determine the overall pool of prospective candidates to enter the "teaching pipeline", even though alternative pathways that enable adults to enter the profession at any point in their lives can mitigate the influence of these factors. The chapter also attempts to explain these differences between countries by relating them to the working conditions, social status and monetary compensation enjoyed by teachers in different countries. Attracting high-achieving students to the teaching profession might be particularly important in countries that suffer from shortages of teachers, or where perceptions of teacher shortages are worsening over time.