Inflammation is central in inflammatory bowel disease (IBD) pathogenesis. Because of diet's pro- and anti-inflammatory properties, multiple observational studies have explored the link between the dietary inflammatory potential and IBD-related outcomes. We aimed to systematically review the literature and provide a comprehensive overview of the dietary inflammatory potential and its association with the development and progression of IBD.Literature was searched systematically on the 2nd of May 2024 in PubMed, Web of Science, Scopus, Cochrane Library, and Embase to identify the observational studies that explored the link between the dietary inflammatory potential and IBD-related outcomes. A higher dietary inflammatory potential was defined as the ability of a dietary pattern to promote inflammation in the body. Studies were included only if they quantified this using a dietary index, such as the dietary inflammatory index (DII) and the empirical dietary inflammatory pattern (EDIP). Two authors independently performed study selection and data extraction and assessed the risk of bias using the Newcastle-Ottawa scale.Fourteen of the 165 identified records met the inclusion criteria. Seven investigated the risk of developing IBD, but with mixed results. Nine investigated the progression of IBD, which indicated that a higher dietary inflammatory potential contributed to higher disease activity and associated symptoms.The evidence suggested that a higher dietary inflammatory potential worsens the condition of IBD patients, while the link with the risk of developing the disease was less clear. To elucidate this, high-quality intervention studies are needed.