Background <p>Kaposi sarcoma (KS) is one of the most common tumors in patients with AIDS, while the occurrence of chylous effusions in KS patients is rare and often indicates a poor prognosis. This report present a case of successfully treated AIDS-associated KS complicated by both chylothorax and chylous ascites, along with a review of the relevant literature.</p> Case presentation <p>A 31-year-old male patient, who was recently diagnosed with HIV infection and oral KS at our clinic center, returned two weeks post-discharge. He reported significant enlargement of the oral tumor, increased abdominal girth with accompanying abdominal distension and pain, and a dry cough over the past week. Upon readmission, CT scans indicated the presence of extensive pleural and abdominal effusions. Aspirates from both the pleural and abdominal effusions exhibited a milky chylous appearance. After eliminating other potential etiologies for the chylous effusion, we associated it with the progression of KS. The patient’s condition was ultimately successfully managed through a combination of antiretroviral therapy, systemic chemotherapy, and ntermittent thoracoabdominal paracentesis for drainage.</p> Conclusions <p>The development of chylous effusions in patients with AIDS-associated Kaposi sarcoma signifies disease progression. Prompt initiation of systemic chemotherapy combined with antiretroviral therapy is critical for improving outcomes.</p>