Background and aims: Patients' outcome after ICU transfer reflect hospital's post-ICU care status. This study assessed association of after-hour ICU transfer on patient outcome. Subjects and methods: Single-centre, retrospective analysis of data between March 2016 to April 2017 at a tertiary-care hospital in India. Patient data were collected on all consecutive ICU admissions during study period. Patients were categorized according to ICU transfer time into daytime(08:00-19:59 hours) and after-hour(20:00-07:59 hours). Patients transferred to other ICUs/hospitals, died in ICU, or discharged home from ICU were excluded. Only first ICU admission was considered for outcome analysis. Primary outcome-hospital mortality; secondary outcomes-ICU re-admission and hospital length of stay (LOS). All analysis were adjusted for illness severity. Results:Of 1857 patients admitted during study period,1356 were eligible for study; 53.9% were males and 383(28%) patients transferred during after-hour. Mean age of two groups (daytime vs. after-hour 65.7 +/- 15.2 vs. 66.3 +/- 16.2 years) was similar (p = 0.7). Mean APACHE IV score was comparable between daytime vs. after-hour transfers (45.6 +/- 20.4 vs 46.8 +/- 22; p = 0.05). Unadjusted hospital mortality rate of after-hour-transfers was significantly higher compared to daytime-transfers (71% vs. 41%; p = 0.02). After adjustment with illness severity, after-hour-transfers were associated with significantly higher hospital mortality compared to daytime-transfers(aOR1.7, 95%0 1.1,2.8; p = 0.04). Median duration of hospital LOS and ICU re-admission though higher for after-hour-transfers, was not statistically significant in adjusted analysis (aOR(hospital-LOS)1.1, 95% CI 0.8, 1.4, p = 0.5; aOR(readmission)1.6, 95% CI 0.9,2.7; p = 0.06 respectively). Conclusion: After-hour-transfers from ICU is associated with significantly higher hospital mortality. Hospital LOS and readmission rates are similar for daytime and after-hour -transfers.