Background There are limited data regarding the criteria for prophylactic treatment of venous thromboembolism (VTE) after hospital discharge. We sought to identify risk factors of post-hospital discharge VTE events following colorectal surgery.Methods The NSQIP database was utilized to examine patients developed VTE after hospital discharge following colorectal surgery during [2005][2006][2007][2008][2009][2010][2011][2012][2013]. Multivariate analysis using logistic regression was performed to quantify risk factors of VTE after discharge.Results We evaluated a total of 219,477 patients underwent colorectal resections. The overall incidence of VTE was 2.1 % (4556). 33.8 % (1541) of all VTE events occurred after hospital discharge. The length of postoperative hospitalization had a strong association with post-discharge VTE, with the highest risk in patients who were hospitalized for more than 1 week after operation (AOR 9.08, P\0.01). Other factors associated with post-discharge VTE included chronic steroid use (AOR 1.81, P\0.01), stage 4 colorectal cancer (AOR 1.40, P = 0.03), obesity (AOR 1.37, P\0.01), age[70 (AOR 1.21, P = 0.04), and open surgery (AOR 1.36, P\0.01). Patients who were hospitalized for more than 1 week after an open colorectal resections had a 12 times higher risk of post-discharge VTE event compared to patients hospitalized less than 4 days after a laparoscopic resection (AOR 12.34, P\0.01).Conclusions VTE is uncommon following colorectal resections; however, a significant proportion occurs after patients are discharged from the hospital (33.8 %). The length of postoperative hospitalization appears to have a strong association with post-discharge VTE. High-risk patients may benefit from continued VTE prophylaxis after discharge.