Abstract Oncoplastic breast surgery (OPBS) is offered to patients with early breast cancer. Local (LR) recurrence following OPBS reported only in case series till date. There is no RCT comparing the incidence of local recurrence (LR) following conventional BCS & OPBS. Aim: Evaluation of incidence of LR & cosmesis following conventional BCS & OPBS Methods: After obtaining IRB approval, over a 2 year period, 94 consenting Women with breast tumors ≤ 4cm were randomised to BCS (group 1: 47 patients) or OPBS (group 2: 47 patients). Patients with no suspicious axillary nodes underwent SLNB & those with nodal metastasis underwent ALND. All surgeries were performed under general anaesthesia. Patients in group 1 underwent ‘standard’ wide local excision with 1 cm tumor free margin following which wound was closed with absorbable sub cuticular sutures. Patients in group 2 underwent level 1 or level 2 oncoplastic breast surgery using volume displacement techniques wherein breast parenchymal plates were mobilized on either sides from underlying pectoral fascia and overlying skin. The cut edges were approximated by absorbable interrupted sutures so as to obliterate the cavity following which skin was closed with absorbable sub cuticular sutures. Cavity margins were marked with titanium clips to facilitate planning of radiotherapy. All patients were discharged on postoperative day 1 & were followed up as per standard protocol. At follow up patients were assessed for surgical site infection, seroma etc. Cosmetic & aesthetic outcome were evaluated by patient herself, a female nurse & surgeon 3 & 6 months after surgery. Aesthetic score was assessed individually using the predetermined criteria viz. shape with brasserie, shape without brasserie, symmetry to the opposite breast, mobility, consistency, position of inframammary fold & NAC and overall appearance. All patients received whole breast RT with boost to cavity site followed by systemic treatment. Statistical Analysis: Qualitative & quantitative data was expressed as frequency , mean +SD, and median (min-max). Categorical & continuous variables were compared among the groups by chi-square, Fischer exact test, independent t test or Wilcoxon rank sum test . P value <0.05 was considered as significant. Results: Mean age of patients was 48.78 years (range 23-76 years SD: 12.29). Tumor size ranged from 1-4 cm ( mean: 2.9 cm; median 3 cm in group 1 & mean 3.14 cm; median 3 cm in group 2). Primary tumor was T1 in 17 (18 %) & T2 in 77 (82%). Node status was N0 in 79 (81%) patients and N1 in 15 (19%). 66 (69.6%) tumors were ER and PR +ve, 21 (22.3%) were triple negative and 8 (8.5%) were Her2 neu positive. 91 (93.61%) were invasive carcinoma and 3 (6.39%) were DCIS. Seven patients (7.4%) received NACT. 79 (81.4%) underwent SLNB and rest underwent ALND. Patient & tumor characteristics were similar in both groups. Local Recurrence: At a mean follow up of 28.02±8.82 ( range 13-47) months, 5 patients (5.3%) developed LR ( 1 in group 1 (2.1%) and 4 in group 2 (8.5%). However, this difference was not statistically significant. Three (3.19%) of these patients ( 1 in group 1 and 2 in group 2) developed systemic metastasis and died. Patients’ satisfaction with surgery and comfort with brassiere were significantly higher in group 2. However, there was no difference in sexual and social life among the two groups. Shape of the breast with & without brassiere, and over all appearance were rated to be significantly better in group 2 by both the surgeon and nurse. Conclusions: Contrary to published literature, in this RCT, LRR following OPBS is slightly higher as compared to conventional BCS. But the difference is not statistically significant. Larger trials with longer follow up are needed to confirm this observation. Cosmetic satisfaction and aesthetic outcome were significantly better with OPBS Citation Format: Seenu V, Devprakash Choudhary, Shivangi Saha, Srineil Vuthaluru, Anurag Srivastava. Local recurrence and aesthetic outcome following conventional breast conserving surgery and oncoplastic breast surgery: A randomized controlled trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-47.