Reproductive isolating barriers are a crucial element in the speciation process. There are various types of barriers, and within those that act early in the speciation process, the behavioral one can play an important role in isolating populations or closely related species. It has been shown that the high diversity of some taxa correlates with the variation of sexual signals, which facilitate isolation. Here it is explored whether chemical signals may contribute to the high diversity of Liolaemus lizards, which has more than 290 species. Population chemical discrimination was investigated in two co-distributed species, L. tenuis and L. lemniscatus. The studied populations were closely located and likely belonged to the same genetic lineages. Lizards of both species discriminated between scents of their own and different populations, and in most cases, scents from their population were preferred. Results suggest a fast evolution of scents, and their recognition, and there for the ethological barriers associated with the chemical modality may evolve fast. However, because the studied species differed in the strength of the exhibited population chemical discrimination, ethological barriers evolve at different rates across species. It can be concluded that ethological barriers involving the chemical modality may disrupt species' cohesion, contributing to Liolaemus diversification, in synergy or not with geographical barriers.