Background: One of the manifestations of recurrence after mastectomy is the presentation of chest wall lesion. However, it is unclear if the size of the chest wall recurrence (CWR) is related to the presence of simultaneous systemic metastasis in these patients. We aimed to determine if the size of the CWR could affect the outcome in these patients.Methods: Stage I-III breast cancer patients who underwent mastectomy and developed invasive ipsilateral CWR were included. Patients with bilateral mastectomy were excluded. Demographic, radiologic and pathological data were analysed between patients with CWR and simultaneous systemic metastasis versus those with isolated CWR.Results: Of the 1,619 patients treated with mastectomy, 214 (13.2%) patients developed recurrences. 57/214 (26.6%) patients had invasive ipsilateral CWR. 48 patients were analysed after exclusion of patients with missing data. Mean age at diagnosis of first cancer and at recurrence were 55.2 years (32-84) and 58.5years (34-85) respectively. 26/48 (54.2%) had CWR with simultaneous systemic metastasis. Mean CWR size was 30.7 mm (6-121) and 21.4 mm (5.3-90) for the patients with simultaneous systemic metastasis and those without respectively (P=0.441). Grade (P=0.0008) and nodal status (P=0.0009) at primary diagnosis, grade (P=0.0011) and progesterone receptor (PR) status (P=0.0487) at recurrence were statistically significant for systemic metastasis in patients with CWR.Conclusions: Biologic factors such as grade of primary and recurrent cancer, PR status of recurrent cancer and nodal status at primary diagnosis, instead of CWR size, were associated with simultaneous systemic metastasis in patients with CWR.