The ability of cancer cells to synthesize and store lipids in the form of lipid droplets (LDs) gives them a proliferative advantage over normal cells. Here, we elucidate the effect of monoethanolamine (Etn) on the lipid metabolism of LD-rich prostate carcinoma (PC3) cells. Etn is a ubiquitous molecule that serves as a phospholipid precursor and has been shown to have anticancer activity, although its mechanism of action is not fully understood. PC3 cells were treated with Etn and evaluated with a combination of biochemical and cell biology techniques. Treatment with Etn caused a decrease in cytosolic LD abundance induced by Ca²⁺-stimulated lipolysis. Our study effectively implicates the disruption of lipid metabolism as a contributor to Etn-induced cell death. This finding opens new avenues for the development of LD-targeted anticancer therapy.