Objective:　To　probe　into　reasons　for　misdiagnosing　pelvic　tumor　as　deep　venous　thrombosis,　as　well　as　diagnostic　methods　and　effective　treatments　for　pelvic　tumor.　Methods:　4　case　reports　on　misdiagnosing　pelvic　tumor　as　deep　venous　thrombosis　and　further　analysis　of　the　causes　of　misdiagnosis,　diagnosis,　and　treatment,　with　study　of　the　literature.　Results:　The　4　cases　misdiagnosed　as　pelvic　tumor　were　actually　fibroneuroma,　myxo-fluidity　Liposarcoma,　moderately　differentiated　squamous　cell　carcinoma,　and　synovial　sarcoma　respectively.　The　tumor　in　the　first　case　was　completely　removed,　and　in　the　other　3　cases　the　malignant　tumors　were　resected　when　the　tumors　shrank　with　clear　boundary　and　less　blood　supply　after　application　of　3　cycles　of　intra-arterial　chemotherapy　via　an　implanted　pump.　Conclusion:　Pelvic　tumor　usually　shows　up　or　is　misdiagnosed　as　deep　venous　thrombosis　because　of　its　untypical　clinical　manifestation,　so　one　should　be　on　the　alert　for　pelvic　tumor　when　deep　venous　thrombosis　occurs.　Tumor　resection　is　preferred　for　benign　tumor,　and　intra-arterial　intervention　chemotherapy　should　first　be　applied　for　malignant　tumor,　followed　by　surgery.　©　Mattioli　1885.