Bulk As-Te-Tl glasses belonging to the As30Te70-xTlx (4≤x≤22) and As40Te60-xTlx (5≤x≤20) composition tie lines are studied for their I–V characteristics. Unlike other As-Te-III glasses such as As-Te-Al and As-Te-In, which exhibit threshold behavior, the present samples show memory switching. The composition dependence of switching voltages (Vt) of As-Te-Tl glasses is also different from that of As-Te-Al and As-Te-In glasses, and it is found that Vt decreases with the addition of Tl. Both the type of switching exhibited by As-Te-Tl glasses and the composition dependence of Vt, seems to be intimately connected with the nature of bonding of Tl atoms and the resultant structural network. Furthermore, the temperature and thickness dependence of switching voltages of As-Te-Tl glasses suggest an electro thermal mechanism for switching in these samples.