In this cohort of patients, we found that TAMs isolated from the ascites of primary high-grade serous ovarian cancer patients presented a prevalence of M1 macrophages (CD14+/CD80+/Glut1+ cells) with a higher M1/M2 ratio than patients with different histotypes or ovarian metastasis from other sites (2.6 ± 0.8 vs 0.99 ± 0.4, 95% CI: 0.74–1.72; p = 0.006). Here, CD80 is linked to ovarian serous adenocarcinoma.