In this paper, the authors present the results of their thermodynamic analysis, regarding gas turbine installations (GTIs) with total water injection in the combustion chamber (CC). Among existing GTIs, the majority are without water or steam injection in the working fluid, while some of them employ partial water/steam injection (GTIWI). The technical solution proposed by the authors, with total water injection (GTITWI), is designed to realize the desired temperature in the CC by means of the injected water exclusively. The introduced air flow is only the quantity strictly needed to produce combustion. As a result, for many cases, we have higher values for the thermal efficiency in a GTITWI compared with the GTIs without water/steam injection. Consequently, from this point of view, GTIWI are situated between GTI and GTITWI. Also, like for all GTIWI, for GTITWI too, using water injection results in much lower values for NOx emissions.