The aim of this study was to investigate the in vitro 24-hour tensile/peel bond strength of glass ionomer cement (GIC) together with the amount of cement left attached to the enamel surface after bond failure. The effect of contamination with moisture during setting/hardening and changing the powder/liquid mixing ratio of the GIC was also studied. Five GIC's (Intact, Fuji II, Orthocem B, ChemFil II, and Ketac Fil[capsulated]) and one composite resin (Concise) were tested by bonding GAC eyelets, with a curved photo-etched base, to the buccal surface of human premolars. Bond strength testing was performed on an Instron 1185 testing machine and the amount of cement left attached to the enamel surface quantified using the ARI index. The tensile/peel bond strengths achieved with all the GIC's were significantly lower than the composite resin (P less than 0.0002). Increasing the powder/liquid ratio resulted, in general, in higher bond strengths, the increase being significant for Intact and Orthocem B (P less than 0.05). Protection from moisture did not significantly affect the bond strength with the exception of Fuji II, for which, there was a significant decrease when the material was mixed at the recommended powder/liquid ratio.