Neuromodulation catheter systems with controlled irrigation capabilities and methods for using such systems are disclosed herein. One such method includes, for example, positioning an irrigated neuromodulation catheter at a treatment site within a renal blood vessel of a human patient, delivering neuromodulation energy at the treatment site, and delivering irrigation fluid to the treatment site having characteristics coordinated with the delivered energy. The characteristics can be adjusted to maintain an energy delivery element and/or tissue of the blood vessel at a constant temperature as power is increased. The method can further include monitoring at least one parameter of the tissue and/or of the energy delivery element, and adjusting the neuromodulation energy and/or the characteristics of the irrigation fluid if the at least one parameter falls outside of a treatment range of values.
