In this work, the effects of Ag substitution for Ti in Zr56Cu24Al9Ni7Ti4-xAgx (x = 0, 1, 2, 3, and 4 at%) bulk metallic glasses (BMGs) on the glass-forming ability, thermal stability and mechanical properties are investigated. The present research shows that the critical diameter increases to 6–8 mm for Ag content of x = 2 and 3 at%. Additionally, with increasing in the content of Ag, with a rod diameter of 3 mm, the glass-forming ability and thermal stability were effectively improved. The largest ultimate fracture strength and plastic strain were observed for alloys where x = 2 with a rod diameter in 3 mm (1863 (± 25) MPa and 7.9 (±0.6) %, respectively). Different fracture modes were observed using scan electron microscopy after compressive testing. This work illustrates that Ag can play an important role in improving glass-forming ability, thermal stability and mechanical properties for amorphous alloys.