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BACKGROUND Short course radiotherapy followed by chemotherapy has not been widely evaluated as an alternative to traditional long course chemoradiotherapy in locally advanced rectal cancer. OBJECTIVE Study comparing oncological and short term outcomes between short course radiotherapy + chemotherapy and long course chemoradiotherapy in locally advanced rectal cancer. DESIGN This is a retrospective propensity matched study. SETTINGS The study was conducted at a colorectal department in a tertiary care oncology center in India. PATIENTS There were 173 patients. Group A had 47 and group B had 126 patients. A 1:2.7 matching was done for age, sex, distance of tumor from anal verge, sphincter preservation surgeries, MRI based pre-treatment T stage and circumferential resection margin (CRM). INTERVENTIONS Short course radiotherapy + chemotherapy (group A) and long course chemoradiotherapy (Group B) in LARC in locally advanced rectal cancer. MAIN OUTCOME MEASURES The primary measures were pathological CRM positivity, downstaging, tumor regression grade, postoperative complications. RESULTS There were 52% patients had positive circumferential resection margin on MRI, 57% low rectal tumors, 20% T4 tumors. Distribution of rectal surgeries was similar between the 2 groups. pT downstaging and tumor regression scores were significantly better in group B (p= 0.028 and 0.026 respectively). Pathological circumferential resection margin, distal resection margin and nodal yield were similar. On Multivariate analysis - pretreatment N status was the only independent predictive factors for pCRM status. Grade 3-4 Clavien-Dindo complications, anastomotic leak rates and hospital stay were similar between the two groups. LIMITATION This was a retrospective study. Although propensity matching was performed, selection bias cannot be eliminated completely as seen in the difference in the surgical approaches between the two groups. CONCLUSIONS In a cohort containing significant portion of MRI circumferential resection margin positive low rectal cancers, short course radiotherapy +chemotherapy followed by delayed surgery resulted in lower T downstaging and lower tumor regression scores compared to long course chemoradiotherapy. But pathological circumferential margin status, distal resection margin, nodal yield and perioperative morbidity were similar between the two groups. This suggests that short course radiotherapy +chemotherapy could be a viable alternative to long course chemoradiotherapy in locally advanced rectal cancers. See Video Abstract at http://links.lww.com/DCR/B855.