Surgical site infection (SSI) is a costly and devastating complication of surgery. Many cardiac SSIs develop after the patient leaves hospital, but evidence demonstrating the benefit of patient/carer involvement in the process of monitoring and promptly identifying SSI post-discharge is limited. This study estimates the probability of readmission for SSI for coronary artery bypass graft (CABG) patients receiving the Photo at Discharge (PaD). Trained personnel undertook continuous, prospective SSI surveillance using Public Health England protocol between January 2013 and December 2016. Baseline covariables were collected for 1747 CABG-only procedures. As a quasi-randomised design, we adjusted for non-random PaD assignment using retrospective propensity score (PS)-matching based on 12 variables of interest, assessed whether the model had been adequately specified and performed an outcomes analysis. A total of 568 patients with PaD were PS-matched with 568 controls. The probabilities of SSI readmission were 0.352 (2/568) and 1.761 (10/568), respectively. The difference in risk of readmission for SSI was significant (relative risk = 0.2, 95% confidence interval = 0.04-0.91; P = 0.04). Findings from this single-centre observation study suggest the PaD is associated with a reduction in CABG readmission for SSI and a further study is warranted to verify the efficacy of this strategy.