Objectives To analyse the lung metastasis and possible factors influencing lung metastasis in alveolar soft part sarcoma (ASPS) patients.Methods The medical records of 64 consecutive ASPS patients were reviewed to analyse their treatments, features of lung metastasis, and possible factors influencing lung metastasis.Results Thirty-six females and 28 males with a median age of 27 years were included.The primary disease sites were the extremities in 51 patients and other locations in 13 patients.The median primary tumour size was 5 cm.Wide local excision of the primary tumour was performed on 56 patients (87.5 %).Thirteen patients (20.3 %) received postoperative adjuvant radiotherapy, and nine patients (14.1%) underwent adjuvant chemotherapy.Twelve patients (18.8 %) presented with metastatic lung disease.Twenty-nine patients (45.3 %) developed metastatic lung disease during follow-up.Lung metastasis occurred in 64.1% of the patients.Lung metastasis was detected at a median interval of 20 months after primary ASPS diagnosis.Being male, >20 years of age, having a primary tumour size ≥5 cm, and local recurrence were associated with a greater rate of lung metastasis.Median survival after the diagnosis of lung metastasis was 34 months.The 5-year survival rates were 64.1 and 95.2 % for patients with and without lung metastasis (P < 0.001).Thirty-seven patients with metastatic lung disease received anthracycline-and ifosfamide-based chemotherapy.One patient experienced a partial remission.Conclusions ASPS patients have a high prevalence of lung metastasis.Sex, age, primary tumour size, and local recurrence are major factors influencing lung metastasis.Chemotherapy is not efficacious in ASPS patients with lung metastasis.