Haplo-HSCT has surpassed HLA-matched HSCT in the last three decades. Haplo-HSCT lagged significantly behind HLA-matched HSCT before 2000. With the breakthrough of the T-cell depletion protocol, the Beijing protocol and the Baltimore protocol, haplo-HSCT has caught up with the outcomes of HLA-matched HSCT. As growing evidence suggests a stronger graft-versus-tumor effect, comparable graft-versus-host disease and comparable quality-of-life when comparing haplo-HSCT with HLA-matched HSCT since 2017, there is now a consensus that haplo-HSCT be given priority in certain indications in 2021, and the story of “a perfect mismatch” continues after then