Dual inhibition of the epidermal growth factor receptor (EGFR) and the human epidermal growth factor receptor 2 (HER-2) is an attractive cancer therapeutic approach. In this study, new series of 4-anilinothieno[2,3-d]pyrimidines were designed, synthesized, and tested as dual EGFR/HER-2 kinase inhibitors. Five compounds (8a, 8b, 8e-g) demonstrated low to submicromolar inhibition of both kinases with IC