Long-term unemployment is an increasing concern in Europe. This paper sheds new light on the development and determinants of long-term unemployment in Estonia over the last two decades, taking a particular focus on the years of economic boom and bust. The analysis is based on the individual level data of the Labour Force Survey. The results of regression analysis show that differences in the socio-demographic characteristics of long-term unemployed became smaller during economic bust compared to economic boom. The region of residence was a significant determinant of long-term unemployment only during economic boom. The risk of becoming long-term unemployed is high for older people, people with a lower level of education and for ethnic minorities at both economic boom and bust.