According to the cancer stem cell (CSC) paradigm, a minor subpopulation of cancer cells with stem-cell properties predominantly underlies tumour progression, therapy resistance, and disease recurrence. Notably, epithelial-to-mesenchymal transition (EMT) is implicated in these processes, and CSCs typically show markers of EMT-programme activation. Herein, the authors outline our current understanding of the links between the EMT programme, the CSC phenotype, metastasis, and drug resistance, and discuss the potential for therapeutic targeting of these facets of tumour biology.