Nonionizing millimeter-waves (MMW) are reported to inhibit cell division of lung cancer cells. In this article, we present a mechanism for the effect of inhibited cell division upon 85-105 GHz MMW irradiation. Strains of cell division model organism Saccharomyces cerevisiae cultured under physiological conditions were analyzed for the effects of MMW exposure. Irradiated cells showed a reduced growth rate than that of control (sham) cells. DNA damage repair mutant (rad52) strain cells were also subjected to MMW exposure to identify the involvement of genomic alteration(s) in this process. Irradiated wild type and rad52 mutant strains showed similar colony growth profiles indicating MMW treatment does not alter genomic DNA. Further, MMW interaction with cytological water was explored as a possible mechanism of action. Cells absorbed more power as compared to plain water. MMW irradiation highly absorbed by the cytological water content likely affects proteomic changes, accounting for the observed effects of inhibited cell division. Irradiations using a standard horn antenna were compared to that of a compact waveguide for increased power which led to complete termination of cell division. Our results provide indications of the development of non-invasive nonionizing irradiation procedures to treat tumor metastasis and control microbial infections.