A study has been made to investigate the effects of free-volume fraction, steady state viscous flow temperature and viscosity on the glass transition and viscous flow behaviour of Cux Zr100−x (x = 40, 50 and 60), NixZr100−x (x = 40 and 50) and CuxTi100−x (x = 40 and 50) amorphous alloys. It was observed that the displacement at Tx increases in the order Cu40Zr60 > Ni40Zr60 > Cu40Ti60. We found that this order can be explained by the free-volume fraction and maximum displacement rate at Tvs. The relationship between viscosity and free-volume fraction below Tx is consistent with Doolittle's empirical formula for the CuZr, CuTi and NiZr systems. It is presumed that the kinetics of free-volume production and annihilation are involved in the thermal stability and glass transition temperature.