Abstract Background: The safety of breast conservation therapy (BCT) has not been demonstrated in large ILC tumors, poten-tially contributing to the higher mastectomy rates seen in ILC. Aim of Study: The aim of our study was to identify patients with of breast ILC measuring 4cm and evaluated difference in recurrence free survival (RFS) between those treated with BCT versus mastectomy. Patients and Methods: This is a retrospective study of patients treated for ILC, 60 consecutive treated women with unilateral Stage I or II invasive lobular breast carcinoma were treated with axillary dissection and either mastectomy or conservative breast therapy (n=30) or BCS (n=30), they were admitted to Surgical Oncology Department and General Surgery Department Sayed Galal University Hospital, Al-Azhar University. Results: Disease free survival after 5-years was 81.3% in BCT group and 87.2% in mastectomy group, and after 10- years was 81.3% in group BCT and 72.1% in mastectomy group. Conclusion: For patients with large size ILC, BCT provides similar tumor control as mastectomy, provided that negative margins are achieved. Our findings can be used to help patients and providers make informed choices about surgical options for ILC, which currently has a higher rate of mastectomy than that of IDC.