Understanding the status of hylid frogs in Mexico is often hindered by a lack of understanding of basic natural history. We report on the natural history and phenology of H. plicata from the Arroyo Los Axolotes, Sierra de las Cruces, state of Mexico, as well as its co-occurence with Ambystoma altamirani. Adult Hyla plicata arrive at the stream in March and April, and oviposition takes place in June. Metamorphosis takes place in September and October. Hyla plicata are found in sites along the Arroyo las Axolotes that are wider and deeper, with higher levels of dissolved oxygen and slower water speeds than sites where they are not found. Their distribution is not affected by water temperature. Hyla plicata used sites with white-yellow and tan-brown substrates more than sites with black substrates. Types of substrates and vegetation at sites with and without H. plicata did not differ. Our results suggest that H. plicata requires stream reaches that are wider, deeper, and with slower flowing water, and that H. plicata and A. altamirani negatively co-occur.