The addition of small amounts of Zn, on the order of 0.50 (wt)/(0), to Al-Li-Cu alloys has been shown to have a significant effect on their corrosion resistance. Consequently, the most recent generation of high-performance Al-Li-Cu-X alloys has trace additions of Zn for improved environmental properties. However, there is little knowledge of the effect of Zn on the aging kinetics or coarsening behavior of the various strengthening precipitates. The Al2LiCu (T-1) phase is an equilibrium (111)(alpha) hexagonal plate precipitate that is the primary strengthening phase in these alloys. In this study we investigated the effect of Zn on the coarsening behavior of T-1 in several Al-Li-Cu-X alloys through isothermal artificial aging experiments and quantitative transmission electron microscopy (TEM). Energy dispersive spectroscopy (EDS) showed that Zn partitioned to the T-1 precipitates resulting in enhanced coarsening resistance when compared with a Zn-free Al-Li-Cu alloy.