Surgical site infections (SSI) in open Hepatopancreatobiliary (HPB) surgery are common complications. They worsen patients' outcomes and prolong hospital stays. Their economic significance in the German diagnosis related groups (DRG) system is mostly unknown. To investigate their economic importance, we evaluated all cases for SSIs as well as clinical and financial parameters undergoing surgery in our centre from 2015 and 2016. Subsequently, we carried out a cost-revenue calculation by assessing our billing data and the cost matrix of the InEK (German Institute for the Payment System in Hospitals). A total of 13.5% of the patients developed a superficial, 9% a deep incisional, and 2.4% of the patients an organ space SSI. Compared with Patients without SSI, Patients with SSI had more comorbidities, were older, and their average length of stay was extended by 19 days (P< .001). The financial loss per SSI-case was euro-7035.65 despite increased reimbursement, which resulted in a calculated total loss for the hospital of euro-802 064.62 in 2015 and 2016. Surgical site infections are common complications of open HPB surgery, which lead to a significant increase in the cost per case. Further prevention strategies need to be developed. Besides, an adjustment of revenues must be demanded.