Plumbagin (PLB) is a naphthoquinone endowed with potential medicinal properties, including anticancer activities. We evaluated the effects of PLB on the viability, cell cycle, autophagy, and apoptosis of endometrial carcinoma Ishikawa cells. The proliferation of cells was significantly inhibited by PLB at 0, 8, 10, and 12 μM. By up regulating the expression of p53 and p21, PLB could block the cell cycle in G2/M phase and down regulate cyclin dependent kinase. The apoptosis in the cancer cells was characterized by noticeable chromatin edge collection, nuclear membrane expansion, and vacuolization. PLB could significantly induce autophagy in cells, and its inhibition ability and apoptosis induction were weakened by the autophagy inhibitor SBI-0206965. Our study suggested that PLB may exert anticancer effects by abrogating PI3K/Akt pathway, which recommends it as a promising future phytotherapeutic candidate for EC treatment.