Use of macroporous synthetic mesh in contaminated ventral hernia repair has become more frequent. The objective of this study is to compare the outcomes of ventral incisional hernia repair with permanent synthetic mesh in contaminated fields to those in a clean field. The Abdominal Core Health Quality Collaborative registry, a prospectively updated longitudinal hernia-specific national database, was retrospectively queried for adults who underwent open ventral incisional hernia repair using light or medium-weight synthetic mesh and classified as clean (CDC Class I) or contaminated (CDC Class II/III). Univariate analysis was used to compare demographic information, hernia characteristics, and operative details. Odds ratios (OR) were calculated using multivariable logistic regression for the primary outcome of 30-day surgical site infection (SSI) and secondary outcomes of 30-day surgical site occurrence (SSO), SSO requiring procedural intervention (SSO-PI), and clinical recurrence at one year. 7219 cases met criteria for inclusion; 13.2% of these were contaminated. 83.4% of patients had follow-up data at 30days and 20.8% at 1year. The adjusted OR for 30-day SSI in contaminated fields compared to clean was 2.603 (95% CI 1.959-3.459). OR for 30-day SSO was 1.275 (95% CI 1.017-1.600) and 2.355 (95%CI 1.817-3.053) for 30-day SSO-PI. OR for recurrence at one year was 1.489 (95%CI 0.892-2.487).Contaminated cases had higher rates of mesh infection (3.9% vs 0.8%, p < 0.001) and mesh removal (7.3 vs 2.5%, p < 0.001) at 1 year. After adjusting for baseline differences, patients undergoing ventral incisional hernia repair using light or midweight synthetic mesh in contaminated fields have higher odds of 30-day SSI, SSO, and SSO-PI than those performed in clean wounds. The odds of recurrence did not statistically differ and further studies with long-term outcomes are needed to better evaluate the best treatment options for this patient population.