Open femoral vessel access is commonly performed in vascular surgery, but surgical site complications (SSCs) occur frequently. The aim of this study is to evaluate the incidence and identify potential risk factors by applying a new standardised definition and grading of various types of groin wound complications. This retrospective analysis includes 201 consecutive patients with 219 vertical groin incisions to expose the femoral vessels for different vascular interventions. A prophylactic drain was placed intraoperatively in almost all incisions (91%). Groin SSCs were defined and graded into four categories according to a modified Clavien-Dindo classification. Potential risk factors were evaluated using univariable analysis. For multivariable analysis, a multiple logistic regression was performed. Cutoff values were determined through ROC analysis. According to the proposed definition, regular postoperative course grade 0 (no SSC) occurred in 163 patients (74.4%), grade 1 (minor SSC) in 10 (4.6%), grade 2 (moderate SSC) in 14 (6.4%), and grade 3/4 (major or life-threatening SSC) in 32 (14.6%) incisions. The incidence of clinically relevant SSCs (grade 2–4) was 21%. Drainage volume was an independent parameter that predicted relevant SSCs with a threshold value of 70 mL/24 h on postoperative day 4 (sensitivity 100%; specificity 67%; AUC = 0.835; p = 0.0004). Groin wound complications following vascular procedures are common. Lymphatic leakage appears to be the most significant, potentially preventable condition associated with relevant SSCs. Prophylactic or early therapeutic interventions should focus on reducing lymphatic morbidity.