In this paper, the necessary and sufficient conditions for three-step iterative sequences with errors to converge to a common fixed point for three asymptotically quasi-nonexpansive mappings is established in convex metric spaces. The results of this paper are generalizations and improvements of the corresponding results of Chang [1] - [3], Kim et al. [8], Liu [9] - [11], Ghosh and Debnath [4], Xu and Noor [15], Shahzad and Udomene [13], Khan and Takahashi [6] and Khan and Ud-din [7].